[High expression of hnRNPAB/Kap1 together promote poor prognosis in HCC].

Objective: To further understand the interaction protein spectrum of heterogeneous ribonucleoprotein AB (hnRNP AB), and to investigate their clinical significance in hepatocellular carcinoma (HCC). Methods: We carried out mass spectrometry to reveal the specific peptides of KRAB-associated protein 1 (Kap1) and hnRNPAB, and verified their interaction by immunocoprecipitation and western blotting. Expression of hnRNPAB/Kap1 proteins were detected by immunohistochemical staining in the tissue microarrays. Categorical data were analyzed by the chi square test or Fisher exact test; enumeration data between groups were compared using Student t-test or Wilcocon signed rank test; the cumulative recurrence and survival rates were evaluated using the Kaplan-Meier method and the differences were assessed using the log-rank test. Results: We identified Kap1 as a molecular partner for hnRNPAB in HCCLM3 cells and HepG2 cells as well. We found that the 5-year survival rate of the Kap1high patients was significantly lower than the survival rate of those of the Kap1low group (36% vs 59% , HR = 1.67, P < 0.001). Similarly, Kap1high HCC patients had the poorest prognosis at 5-years, with higher cumulative recurrence rate than Kap1low patients (72% vs 54%, HR = 1.66, P = 0.001). Univariate and Multivariate analyses revealed that hnRNPAB /Kap1 alone (HR = 1.35 /1.28, P = 0.001) or in combination with Kap1 (HR =1.24 /1.27, P < 0.05) were independent prognostic indicators for overall survival and time to recurrence. Conclusion: In HCC cells, hnRNPAB and Kap1 form protein complexes. The expression levels of hnRNPAB alone or in combination with Kap1 in HCC patients are important because they provide not only a predictor for HCC prognosis but also a therapeutic target for future studies.

Identifying significant pathways of hepatitis B virus-related hepatocellular carcinoma based on crosstalk and network pathways.

This study aims to identify significant pathways in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) based on the pathway network strategy. We proposed a pathway network where a protein-protein interaction (PPI) network was integrated with the crosstalk of pathways. Pathway data were first obtained from background PPI network, Reactome pathway database, and common genes between mRNA differentially expressed genes (DEGs), and miRNA target genes of HBV-related HCC. Pathway interactions were subsequently randomly extracted based on gene-gene interactions, and a weight value was assigned to each crosstalk using the Spearman correlation coefficient. Finally, pathways and crosstalk were visualized via Cytoscape to construct the final pathway network. A total of 9 common genes were identified between 396 mRNA DEGs and 400 miRNA target genes, and 17 pathways were identified based on background pathways and common genes. In addition, we constructed a pathway network that included 136 interactions and 17 pathways. The weight value of netrin-1 signaling and regulation of Frizzled proteins (FZD) by ubiquitination was the largest, at 0.228. In conclusion, we identified 17 significant pathways that might act as potential biomarkers of HBV-related HCC. This information may offer some insight into treatment and detection of HBV-related HCC.

Lack of clinical significance of the ImmuKnow(TM)-Cylex assay for the detection of cellular immune function in patients with renal cell carcinoma.

This study aimed to explore the clinical value of the CD4(+) T cell ATP levels in patients with renal cell carcinoma through the application of the ImmuKnow(TM)-Cylex(®) assay. We recruited 104 patients with renal cancer who had undergone surgery at Fuzhou General Hospital from March 2009 to June 2012, and were subsequently treated by dendritic cell and cytokine-induced killer cell bio-therapy or interferon-α therapy. The changes in CD4(+) T cell ATP levels were detected at the perioperative period and at 10 days, 1 month, 3 months, and 1 year after the surgery using the ImmuKnow assay. In addition, the differences in ATP levels in different therapy groups were compared and the prognosis conditions were analyzed. Our results demonstrated that no significant difference in the ATP levels occurred at different time points; furthermore, there were no obviously different ATP levels between the different therapy groups, and the ATP levels were found to have no clinical significance for the assessment of renal cancer prognosis. Overall, this study suggested that CD4(+) T cell ATP levels as detected by the ImmuKnow assay have no obvious clinical value in patients with renal cancer.

Correlation between sheep YAP1 temporal and spatial expression trends and MSTN and MyoG gene expression.

The aim of the current study was to investigate the effects of Yes-associated protein 1 (YAP1) gene expression after birth on the development of muscle and the relationship between YAP1 and myostatin (MSTN) and myogenin (MyoG). Reverse transcription polymerase chain reaction was used to analyze the trends in YAP1, MSTN, and MyoG temporal and spatial expression levels in various skeletal muscles (i.e., longissimus dorsi muscle, soleus muscle, gastrocnemius muscle, and extensor digitorum longus) and across 3 different growth stages (i.e., 2 days old, 2 and 6 months old) of Hu Sheep. The results showed that YAP1 expression was significantly different in the skeletal muscles of sheep; the expression level gradually increased with age; it was highly expressed in the gastrocnemius muscle and minimally expressed in the longissimus dorsi muscle. MSTN, a negative regulator of skeletal muscle development, was minimally expressed in the soleus muscle and might be related to the enlargement of muscle fiber diameter. MyoG, an important factor in regulating skeletal muscle development, was minimally expressed in the longissimus dorsi muscle and extensor digitorum longus, and highly expressed in the gastrocnemius and soleus muscles; it might inhibit the enlargement of muscle fiber diameter after birth. YAP1 expression was significantly (P < 0.05) or extremely significantly (P < 0.01) and positively correlated with MSTN and MyoG at 2 days old, 2 and 6 months old. YAP1 expression was related to muscle fiber development after birth and might be a candidate gene for the regulation of muscle growth.

Association between DLK1 and IGF-I gene expression and meat quality in sheep.

The aim of the present study was to detect delta-like 1 ho-molog (DLK1) and insulin-like growth factor-I (IGF-I) gene expression in the longissimus dorsi of Hu sheep at different growth stages and study the association between these genes and meat quality. The diameter and density of muscle fibers and tenderness of the longissimus dorsi were measured. Growth stage, but not sex, significantly affected DLK1 and IGF-I expression. DLK1 and IGF-I expression in the sheep longissimus dorsi gradually increased with growth, but also decreased during some periods. These results suggest that different growth stages significantly affect DLK1 and IGF-I gene expression in sheep muscle tissue. The ex-pression of DLK1 and IGF-I genes were positively and significantly (P < 0.01) correlated with muscle fiber diameter and muscle fiber shear stress, and negatively and significantly (P < 0.01) correlated with muscle fiber density. Muscle fiber diameter was positively and significantly (P < 0.01) correlated with muscle fiber shear stress, and negatively and significantly (P < 0.01) correlated with muscle fiber density. In addition, DLK-1 expression was significantly (P < 0.01) and positively correlated with IGF-I expression.

Developmental changes in IGF-I and MyoG gene expression and their association with meat traits in sheep.

In the present study, real time-polymerase chain reaction was applied to analyze the expression of IGF-I and MyoG genes in Hu sheep longissimus dorsi at different growth stages and their association with meat traits. Expression of the IGF-I gene in Hu sheep differed significantly between males and females at the two day-old (0.01 < P < 0.05), one-month old (0.01 < P < 0.05), and three month-old (P < 0.01) stages. IGF-I gene expression in male longissimus muscles was higher than that of females at all growth stages, except for the three month-old stage. There was no significant difference (P > 0.05) between males and females at any growth stage in expression of the MyoG gene. MyoG gene expression in male longissimus muscles tended to be higher than that of females at all growth stages, except for the six month-old stage. IGF-I gene expression was significantly and positively correlated with live weight (P < 0.01) and carcass weight (0.01< P < 0.05), and was non-significantly positively correlated with net meat weight (P > 0.05). In contrast, MyoG gene expression was non-significantly and positively correlated with live weight, carcass, and net meat weight (P > 0.05). Carcass traits showed highly significant positive correlations (P < 0.01). Furthermore, expressions of IGF-I and MyoG genes showed highly significant positive correlations (P < 0.01). We conclude that the expressions of IGF-I and MyoG genes are significantly and positively correlated with early muscle traits of Hu sheep.

The antibacterial effect and physical performance of pit and fissure sealants based on an antibacterial core-shell nanocomposite.

The application of pit and fissure sealants is a well-established method to prevent and treat early childhood caries. Resin-based sealants with antibacterial properties provide additional benefits for caries prevention in a cariogenic oral environment. The objective of this study was to evaluate the effect of an antibacterial core-shell AgBr/cationic polymer nanocomposite (AgBr/BHPVP) on the properties of a resin-based pit and fissure sealant. A commercialized pit and fissure sealant without fluoride, Concise (3M, ESPE, USA), was used as the parent material and negative control. Experimental antibacterial sealants were formulated by the addition of AgBr/BHPVP nanoparticles at mass fractions of 0.5, 1.0, and 1.5 wt% to the parent material. A fluoride-releasing sealant, Clinpro (3M, ESPE), was used as the positive control. Bacterial colony-forming unit (CFU) counts, metabolic activity tests, field emission-scanning electron microscopy (FE-SEM), and confocal laser scanning microscopy (CLSM) observations were used to evaluate the antibacterial properties of AgBr/BHPVP-modified sealants against Streptococcus mutans before and after five months of aging. The Vickers microhardness, degree of conversion, and microleakage level of the sealants were also investigated. According to the results of CFU counts and metabolic tests, sealants containing AgBr/BHPVP showed better contact-killing bactericidal activity against S. mutans than the two commercial sealants, irrespective of aging conditions (both P < 0.05). The AgBr/BHPVP-modified sealants also showed a significant inhibitory effect on the planktonic S. mutans around the cured sealant surfaces. In addition, the Vickers microhardness, degree of conversion, and microleakage level of the parent material were not damaged by modification with AgBr/BHPVP (P > 0.05). AgBr/BHPVP-modified pit and fissure sealant with a dual bactericidal mechanism is a promising option for the prevention of pit and fissure caries.

A novel dentin bonding scheme based on extrafibrillar demineralization combined with covalent adhesion using a dry-bonding technique.

Dentin bonding is a dynamic process that involves the penetration of adhesive resin monomers into the extrafibrillar and intrafibrillar demineralized collagen matrix using a wet-bonding technique. However, adhesive resin monomers lack the capacity to infiltrate the intrafibrillar space, and the excess water that is introduced by the wet-bonding technique remains at the bonding interface. This imperfectly bonded interface is inclined to hydrolytic degradation, severely jeopardizing the longevity of bonded clinical restorations. The present study introduces a dentin bonding scheme based on a dry-bonding technique, combined with the use of extrafibrillar demineralization and a collagen-reactive monomer (CRM)-based adhesive (CBA). Selective extrafibrillar demineralization was achieved using 1-wt% high-molecular weight (MW) carboxymethyl chitosan (CMCS) within a clinically acceptable timeframe to create a less aggressive bonding substance for dentin bonding due to its selectively extrafibrillar demineralization capacity. CMCS demineralization decreased the activation of in situ collagenase, improved the shrinking resistance of demineralized collagen, and thus provided stronger and more durable bonding than traditional phosphoric acid etching. The new dentin bonding scheme that contained CMCS and CBA and used a dry-bonding technique achieved an encouraging dentin bonding strength and durability with low technical sensitivity. This bonding scheme can be used to improve the stability of the resin-dentin interface and foster the longevity of bonded clinical restorations.

Gene polymorphisms of SOCS1 and SOCS2 and acute lymphoblastic leukemia.

OBJECTIVE: Acute lymphoblastic leukemia (ALL) causes the dysfunction of the systemic blood system and immune system. The etiology and predisposing factors of ALL are unknown. The suppressor of cytokine signaling 1 (SOCS1) and SOCS2 are inhibitors of cytokine signal transduction. Gene polymorphisms of SOCS1 and SOCS2 and their expressions may be related to ALL. PATIENTS AND METHODS: A total of 200 ALL patients in our hospital and 200 healthy people were enrolled in ALL group and control group, respectively. Genomic deoxyribonucleic acids (DNAs) and total RNAs were extracted from the peripheral blood of each subject. Gene polymorphisms of SOCS1 at rs33977706, rs243327, and rs33932899 and those of SOCS2 at rs3816997 were amplified by polymerase chain reaction (PCR) and sequenced. Besides, the expression levels of SOCS1 and SOCS2 in ALL patients were detected by real-time fluorescence quantitative PCR. RESULTS: The frequency of the allele C of SOCS1 rs33977706 in ALL group was lower than that in the control group, displaying a significant difference between the two groups (p=0.015). The frequency of allele A of SOCS2 rs3816997 was notably higher in ALL group than that of the control group (p=0.000). In addition, the frequency of CA genotype of SOCS1 rs33977706 in ALL group was markedly lower than that in the control group, showing a significant difference (p=0.000). ALL group had remarkably higher frequencies of AA genotype of SOCS2 rs3816997 (p=0.000) and ACC haplotype of SOCS gene (p=0.000), and lower frequencies of ATG (p=0.026) and CCC (p=0.006) haplotypes. The two loci, SOCS1 rs33932899 and SOCS1 rs243327, were linked to each other (D'=0.781). Moreover, the expression level of SOCS1 in ALL group was lower than that in the control group, in which the expression of the CT genotype of SOCS1 rs243327 was relatively higher (p=0.021). SOCS2 level was lower in ALL group. Particularly, SOCS2 level in ALL patients carrying AC genotype was lower than those carrying AA and CC genotypes (p=0.000). ALL patients carrying CT genotype of SOCS1 rs243327 had shorter period of agranulocytosis (p=0.000), a lower ratio of bone marrow primitive/immature cells (p=0.001), and a higher hemoglobin (Hb) level in blood (p=0.000). The ratio of bone marrow primordial/immature cells was lower in ALL patients with AC genotype of SOCS2 rs3816997 (p=0.038). CONCLUSIONS: The expression levels of SOCS1 and SOCS2 are prominently related to ALL, and their polymorphisms are associated with the susceptibility to ALL.

[HIV/AIDS related frailty syndrome in the elderly and related research progress].

Frailty syndrome, caused by degenerative changes in the body and the body vulnerability due to a variety of chronic diseases, is associated with adverse outcomes, such as fall, disability and mortality. With the development of antiretroviral therapy, the average life span of HIV/AIDS patients is extended, the number of elderly living with HIV/AIDS has increased, resulting the increase of the incidence of frailty syndrome in this population. The incidence of frailty syndrome in the elderly is associated with HIV infection and adverse reaction of antiretroviral therapy. Early assessment and intervention of frailty syndrome in elderly HIV/AIDS patients can reduce adverse clinical events and improve the quality of life.

One year results of preoperative single bolus ATG-Fresenius induction therapy in sensitized renal transplant recipients.

UNLABELLED: Sensitization in kidney transplantation is associated with more acute rejections, inferior graft survival, and an increase in delayed graft function. This study was designed to evaluate the efficacy and safety of preoperative single bolus antithymocyte globulin (ATG) induction therapy in sensitized renal transplant recipients. METHODS: Fifty-six cadaveric donor kidney transplant recipients were divided into two groups: Group I (nonsensitized group, n = 30) and group II (sensitized group, PRA>10%, n = 26). ATG was given as a single preoperative bolus induction therapy to group II (ATG IV; 9 mg/kg). The group I patients were treated with mycophenolate mofetil preoperatively as induction therapy. The basic immunosuppressive regimen included tacrolimus (FK-506) or cyclosporine, mycophenolate mofetil, and prednisolone. After hospital discharge, patients were followed on a routine outpatient basis for 12 months. RESULTS: Acute rejection episodes (ARE) occurred in 20% (6/30) of group I and 15.38% (4/26) of group II patients (P = NS). Infections occurred in eight patients (26.7%) as 11 episodes (36.7%), averaging 1.4 episodes per infected patient in group 1, and 6 patients (23.1%) for a total of 10 episodes (38.5%), averaging 1.7 episodes per infected patient, in group II (P = NS). Occurrence of side effects and hospital stay were almost comparable in the two groups. No delayed graft function was observed in either group. The 12-month actuarial patient and graft survival were 100% in Group I and II. CONCLUSION: A preoperative single bolus ATG induction therapy was an effective and safe therapeutic measure, yielding an acceptable acute rejection rate in presensitized renal transplant recipients.

Epidemiologic features of Schistosoma japonicum among fishermen and other occupational groups in the Dongting Lake region (Hunan Province) of China.

In this study we examined 1,909 individuals (53% males and 47% females) to determine the current status of Schistosoma japonicum among the people in five fishing villages situated on two islands (large, Qingshan island; small, Niangashan island) in the Dongting Lake region in Hunan Province, the People's Republic of China. The results of this study indicate that the overall prevalence for schistosomiasis on the two islands is 16%. Two distinct peaks in prevalence (29%) were observed at 25-35 years of age and again at 45-55 years of age for both the large and small islands. On the small island the overall prevalence (24%) varied significantly (P < 0.01) from the large island (15%). Fishermen had the highest prevalence (22.4%) among all the occupational groups examined but students produced the highest worm intensity (geometric mean = 69 eggs per gram [epg] of feces). There was a significant difference (P < 0.01) in the prevalence of schistosomiasis between males and females. In general, males had a much higher prevalence (22%) than females (8.9%). When the study populations were classified as uninfected, lightly infected (10-100 epg), moderately infected (101-400 epg), and heavily infected (> 401 epg) with S. japonicum, the distribution pattern was similar for each of the five villages. The majority (76-88%) of the population remains uninfected. Lightly infected individuals had the highest prevalence (7-12%) followed by moderately infected individuals (1-9%). Only a very small percentage of the population was heavily infected (0-2%). Hepatomegaly along the midsternal line (MSL > or = 3) was commonly seen in both uninfected (21%) and infected individuals (1939%). Subjects heavily infected with S. japonicum reported significantly higher (P < 0.05) cases of liver enlargement when compared with those uninfected. The reported cases of abdominal pain for both uninfected (9%) and infected individuals (4-19%) was relatively high. Lightly and moderately infected individuals reported significantly (P < 0.05 and P < 0.01, respectively) more episodes of abdominal pain than those uninfected. The occurrence of diarrhea was low (5%) for uninfected individuals but this clinical feature was significantly (P < 0.01) more prevalent in both the lightly and heavily infected categories (8-17%).

Computer-assisted peak recognition for polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in environmental samples.

A software has been developed for the peak recognition of 136 polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) after high resolution gas chromatography coupled with mass spectrometry (HRGC/HRMS). Based on the retention times of (13)C labelled 2,3,7,8-substituted PCDD/F internal standards, the retention times of all PCDD and PCDF can be calibrated automatically and accurately. Therefore, it is very convenient to identify the peaks by comparing the retention of samples and the calibrated retention times of their chromatograms. Hence, this approach is very significant because it is impossible to obtain always a standard chromatogram and PCDD/F analysis are very expensive and time consuming. The calibration results can be transferred to Excel for calculation. The approach is a first step to store costly and environmentally relevant data for future application.

Persistence of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in Ya-Er Lake area, China.

The concentrations of polychlorinaxed dibenzo-p-dioxins and dibenzofurans (PCDD/F) in surface sediment, soil, human hair, and fish muscle from Ya-Er Lake area, China, were analyzed. The results showed that there were very high concentrations of PCDD/F existing in these samples. The results also indicated that Ya-Er Lake, which received a large amount of waste water from a nearby chloroalkali plant, was heavily polluted by PCDD/F. The present study demonstrated that those congeners, which possess at least three chlorine atoms in the lateral position with a fourth chlorine atom in the neighborhood bond of the third single chlorine atom, such as 1,2,7,8-TCDF and 2,3,6,7-TCDF, were very resistant to biodegradation due to the "neighbor effect" of every two chlorine atoms. The present study suggested that human hair may be a suitable alternative bioindicator for detecting PCDD/F exposure.

Bioaccumulation of polychlorinated dibenzo-p-dioxins and dibenzofurans in the foodweb of Ya-Er Lake area, China.

Bioaccumulation of PCDD/F in the foodweb was investigated in the Ya-Er Lake area, which was heavily polluted by PCDD/F. The high concentrations of PCDD/F in sediment can be transferred and bioaccumulated by aquatic organisms and humans through various pathways. Benthonic invertebrate animals and aquatic plants with a lot of fibers in the root can accumulate PCDD/F from sediment and water. Snail (Bellamya aeruginosa), shrimp (Macrobranchium sp.) and freshwater mussel (Acuticosta chinensis (Lea)) took up PCDD/F from the water and maintained the emission patterns, whereas fish tended to selectively accumulate 2,3,7,8-substituted isomers. The tissues of fish-eating bird and duck (Anas platyrhynchos) were very highly contaminated by PCDD/F due to ingestion of fish and other aquatic organisms from sediment. The residual concentration in breast milk depended on the original concentration of PCDD/F in the food. A resident in Ya-Er Lake area showed a daily intake of PCDD/F of about 9.14 pg TEQ/kg body weight/day. This is higher than the tolerable daily intake (TDI) for PCDD/F (1 pg TEQ/kg body weight/day), which was recommended by the World Health Organization (WHO).

Mobility and profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans in sediment of Ya-Er Lake, China.

The sediment of Ya-Er Lake had been heavily polluted by polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from the former chloralkali industry. The total amounts of PCDD/Fs and I-TEQ decreased along the water flow direction and also decreased from top to bottom layers of sediment cores. Sediment of Pond 1 was dominated by PCDF. especially TCDF. In contrast, in the other four ponds, PCDD dominated in all layers and octachlorinated dibenzo-p-dioxin (OCDD) predominated in all of the homologues. When homologue profiles from sediments and water samples were compared using principal component analysis (PCA), the first two principal components represented 95.2% of the variance in the data. The first component explained 75.9% of the variance and the second one 19.3%. Two clusters were most distinct, presenting a shift in PCDD/Fs composition from PCDF to heptachlorinated dibenzo-p-dioxin (HpCDD) and OCDD in sediments and water from Pond I to Ponds 2-5. The pattern variation between Pond I and Ponds 2-5 in Ya-Er Lake was most likely due to the change of process in the chemical plant after the dams between the ponds were built. The results of the present study also showed that log Koc of PCDD/Fs calculated from data of sediment and water in the field were comparable with theoretical log Koc. The results also implied that the concentrations of PCDD/Fs in water and sediments could be predicted from each other by log Koc.

The study on the expression of membrane HSP70 protein in H22 cell and its immunoprotective mechanism against carcinoma.

The mRNA and protein expression of HSP70 were studied using RT-PCR and FCM techniques. It's immune protective effects in vivo and the cytotoxicity in vitro were also observed. Results showed that cell viability didn't change under 42-43 degrees C, but declined in 44-45 degrees C; the level of HSP70 mRNA decreased initially (0.5-4.0 hour) but gradually resumed and increased from 8 to 12 hours at 42 degrees C. The positive cells expressed membrane HSP70 were significantly higher in heat shocked group than in a control group (P<0.001); the highest positive rate was 96.8% at 43 degrees C. The C3H mice immunized with heat shocked H22 cells could resist a secondary subcutaneous inoculation of parental H22 cells and their tumorigenic rate was significantly lower than that in mice immunized with parental H22 cells and RPMI 1640 control mice, which were 1/9.7/8 and 8/8, respectively. Their median survival time was also longer than that of parental cell group and RPMI 1640 control group, which were >90 days, 73.5 days, and 39.5 days, respectively. Through heat-treated tumor cell and lymphocyte mixed culture (TLMC), the induced lymphocytes had higher cytotoxic activities than that of splenic cells. The cytotoxicity against H22 cells reached 65.38% (2 hrs, 42 degrees C) and 67.84% (12 hrs, 43 degrees C) and could be blocked by anti-HSP70 McAb. Phenotype analysis revealed that the rate of TCR gammadelta+ cells rose with increasing cytotoxic activity, but no similar changes could be found in the CD4+ CD8+ TCR alphabeta+ subset. These results suggest that proper heat shock conditions can improve the immunogenicity of tumor cells and CD4- CD8- TCR gammadelta+ T carried on cytotoxic function via the HSP70 molecule.

Quantitative relationships between molecular structures, environmental temperatures and octanol-air partition coefficients of PCDD/Fs.

A concise quantitative model that incorporates information on both environmental temperature (T) and molecular structures, for logarithm of octanol-air partition coefficient (K(OA)) to base 10 (logK(OA)) of PCDDs, was developed. Partial least squares (PLS) analysis together with 14 quantum chemical descriptors were used to develop the quantitative relationships between structures, environmental temperatures and properties (QRSETP) model. It has been validated that the obtained QRSETP model can be used to predict logK(OA) of other PCDDs. Molecular size, environmental temperature (T), q+ (the most positive net atomic charge on hydrogen or chlorine atoms in PCDD molecules) and E(LUMO) (the energy of the lowest unoccupied molecular orbital) are main factors governing logK(OA) of PCDD/Fs under study. The intermolecular dispersive interactions and thus the size of the molecules play a leading role in governing logK(OA). The more chlorines in PCDD molecules, the greater the logK(OA) values. Increasing E(LUMO) values of the molecules leads to decreasing logK(OA) values, implying possible intermolecular interactions between the molecules under study and octanol molecules. Greater q+ values results in greater intermolecular electrostatic repulsive interactions between PCDD and octanol molecules and smaller logK(OA) values.

Accumulation and partition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in the muscle and liver of fish.

The present study monitored fish from sites contaminated for many years, and the data reflected the results of actual, long-term environmental exposure. The sum concentrations and TEQs of PCDD/F in the muscle of common carp (Cyprinus carpio (linnaeus)) and big head (Aristichthys nobilis) from the different site of a heavily polluted lake in China are decreased with decrease of PCDD/F concentration in sediment and water. Concentration in fish can be highly variable, but the concentration is comparable in muscle between different species of fish if the concentrations are normalized by lipid content. PCDD/F accumulate in certain tissues with the highest proportions found in the liver of fish. The concentrations and TEQs in livers were also decreased with concentrations of sediments and water. The concentrations of PCDD/F in muscle are significantly correlated with those in liver. BCFs of 2,3,7,8-substituted PCDD/F calculated directly from water were consistent with that calculated indirectly from sediment. PCDD/F concentrations in sediment are much higher than that in water, therefore the measurement is much easier and the results are more accurate. Estimated BCFs for superhydrophobic chemicals derived from sediment may also serve as acceptable surrogates for "true" bioaccumulation potential.

A new enzyme immunoassay for PCDD/F TEQ screening in environmental samples: comparison to micro-EROD assay and to chemical analysis.

A new Enzyme ImmunoAssay (EIA) for PCDD/F TEQ measurement in extracts of environmental samples was described. The bioassay TEQ which derived from EIA and EROD were compared with each other and with results from chemical analysis. For all environmental samples, the EROD-TEQ is higher than the value from chemical analysis. However, the EIA-TEQ is much more identical with the value from chemical analysis. Our results indicate that the EIA assay is a complementary method to the EROD assay and should be useful as a rapid and sensitive screening tool for environmental samples in many situations.