Spectroscopic and chromatographic characterization of wastewater organic matter from a biological treatment plant

Spectroscopic and chromatographic changes in dissolved organic matter (DOM) characteristics of influent and treated sewage were investigated for a wastewater treatment plant (WWTP) with a biological advanced process. Refractory DOM (R-DOM) was defined as the dissolved organic carbon concentrations of the samples after 28-day incubation for this study. Specific UV absorbance (SUVA), hydrophobicity, synchronous fluorescence spectra and molecular weight (MW) distributions were selected as DOM characteristics. The percent distribution of R-DOM for the effluent was much higher than that of the influent, indicating that biodegradable DOM was selectively removed during the process. Comparison of the influent versus the effluent sewage revealed that SUVA, fulvic-like fluorescence (FLF), humic-like fluorescence (HLF), the apparent MW values were enhanced during the treatment. This suggests that more aromatic and humic-like compounds were enriched during the biological process. No significant difference in the DOM characteristics was observed between the original effluent (i.e., prior to the incubation) and the influent sewage after the incubation. This result suggests that the major changes in wastewater DOM characteristics occurring during the biological advanced process were similar to those for simple microbial incubation.

Uterine and placental expression of TRPV6 gene is regulated via progesterone receptor- or estrogen receptor-mediated pathways during pregnancy in rodents

Transient receptor potential cation channel, subfamily V, member 6 (TRPV6) is an epithelial Ca2+ channel protein expressed in calcium absorbing organs. In the present study, we investigated the expression and regulation of uterine and placental TRPV6 during gestation in rodents. Uterine TRPV6 peaked at pregnancy day (P) 0.5, P5.5 and, P13.5 and was detected in uterine epithelium and glands of rats, while placental TRPV6 mRNA levels increased in mid-gestation. Uterine and placental TRPV6 mRNA levels in rats appear to cyclically change during pregnancy, suggesting that TRPV6 may participate in the implantation process. In addition, uterine TRPV6 mRNA is only expressed in placenta-unattached areas of the uterus, and uterine TRPV6 immunoreactivity was observed in luminal and glandular epithelial cells. In the placenta, TRPV6 was detected in the labyrinth and spongy zone. These results may indicate that TRPV6 has at least two functions: implantation of the embryo and maintenance of pregnancy. To investigate the pathway(s) mediating TRPV6 expression in rodents, anti-steroid hormone antagonists were injected prior to maximal TRPV6 expression. In rats, TRPV6 expression was reduced by RU486 (an anti-progesterone) through progesterone receptors, and ICI 182,780 (an anti-estrogen) blocked TRPV6 expression via estrogen receptors in mice. The juxtaposition of uterine and placental TRPV6 expressed in these tissues supports the notion that TRPV6 participates in transferring calcium ions between the maternal and fetal compartments. Taken together, TRPV6 gene may function as a key element in controlling calcium transport in the uterus between the embryo and the placenta during pregnancy.

Predicting the ideal serum creatinine of kidney transplant recipients by a simple formula based on the balance between metabolic demands of recipients and renal mass supply from donors

Serum creatinine (Scr) is the most frequently used test to estimate graft function after kidney transplantation. Our previous study demonstrated that the independent predictors of recipient posttransplantation Scr included the ratio of graft weight to recipient body weight, the ratio of graft weight to recipient body surface area (BSA), and the ratio of graft weight to recipient body mass index (BMI). A prospective analysis about the impact of the balance between metabolic demands and renal supply on posttransplantation Scr of recipients was previously reported. We plotted the scatter graph using the X-axis as the independent predictors of Scr by linear regression and the Y-axis as the recipient Scr. To generate the predictive formula of Scr, we calculated a fit of the line of plotted cases using a linear regression method with 2 regression lines for prediction of the upper and lower 95% confidence intervals. Each line was converted into a predictive formula: Scr = -0.0033* (Graft weight(g)/Recipient BSA(m2))+1.75. Under 95% confidence, the Scr ranges from -0.0033* (Graft weight(g)/Recipient BSA(m2))+1.07 to -0.0033* (Graft weight(g)/Recipient BSA (m2))+2.44. Scr = -0.1049* (Graft weight(g)/Recipient body weight(kg))+1.72, which ranges from -0.1049* (Graft weight(g)/Recipient body weight(kg))+1.06 to -0.1049* (Graft weight(g)/Recipient body weight(kg))+2.37. Scr = -0.0158* (Graft weight(g)/Recipient BMI(kg/m2))+1.56, which ranges from -0.0158* (Graft weight(g)/Recipient BMI(kg/m2))+0.75 to -0.0158* (Graft weight(g)/Recipient BMI(kg/m2))+2.26. Prediction of posttransplantation Scr may be achieved by measuring graft weight as well as recipient weight and height. When recipient Scr is significantly higher than that predicted by the formula, a clinician should suspect an underlying graft injury.

Preparation of doxorubicin-containing chitosan microspheres for transcatheter arterial chemoembolization of hepatocellular carcinoma

A new form of doxorubicin hydrochloride (DRH)-containing chitosan microspheres (CMs) was prepared by employing an expanding-loading-shrinking (E-L-S) process. One hundred mg of pre-formed CMs were soaked in absolute ethanol and then placed in reduced pressure (the expanding process). Ten mg of DRH (2 mg ml(-1)) were added into the expanded CMs (the loading process). Next the microspheres were freeze-dried (the shrinking process). As a result of this E-L-S process, 10% (w/w) DRH-containing CMs (DRH-CM) were made. During 7 days, 22.6% of the DRH was observed to be released on the in vitro drug release study. In addition, these new DRH-CMs could be used for transcatheter arterial chemoembolization (TACE) procedure in VX2 hepatic tumour models of rabbit and the anti-tumour effects of DRH-CMs were investigated. On the post-CT scan 7 days after the TACE, total infarctions of the VX2 tumour were observed in 5 rabbits among the 6 total rabbits.

Interesterification of olive oil with a fully hydrogenated fat in a batch reactor using step changes in temperature

Interesterification of a 60:40 (wt/wt) mixture of olive oil and fully hydrogenated canola oil was carried out in a batch reactor using a commercial immobilized lipase from Thermomyces lanuginose as a biocatalyst. The effects of a stepwise change of temperature on the degree of conversion, the solid fat content (SFC) of the products, and the residual activity of the enzyme were investigated. As a reference condition, an interesterification trial was conducted at a constant temperature of 70 degrees C for 48 h. For trials in which a temperature of 70 degrees C was used for the first 4 h of reaction and a temperature of 60 degrees C was employed for the following 44 h, there were no significant differences (p < 0.05) in the overall degree of conversion relative to the reference condition. Oils interesterified for only 1 or 2 h at 70 degrees C had melting points higher than 60 degrees C, whereas an oil produced by interesterification at 70 degrees C for only 4 h had a melting point of 58 degrees C. There was little difference (p < 0.05) between the SFC profiles of the interesterification products prepared by two different temperature protocols (70 degrees C for 24 h; 70 degrees C for 4 h followed by 60 degrees C for 20 h). Use of the protocol involving a step decrease in temperature significantly decreased catalyst deactivation effects, thereby increasing the residual activity of the immobilized lipase.

Implantation-related expression of epidermal growth factor family molecules and their regulation by progesterone in the pregnant rat

The uterine expressions of epidermal growth factor(EGF) family are examined to elucidate their exact role(s) in rat pregnancy. EGF and its receptors' (EGF-R) mRNA levels increased significantly at implantation after which their expression gradually decreased. Heparin-binding EGF (HB-EGF) and transforming growth factor-alpha (TGF-alpha) showed a modest expression at gestation day (GD), GD4 and GD3, respectively, but were much strongly expressed at mid-pregnancy.Amphiregulin (Areg) was strongly expressed around implantation (GD4) and at mid-pregnancy (GD12).Treatment of pregnant rats with RU486 at GD5 or GD8 blocked the expression of all the genes, and administration of immature rats with progesterone (P4) induced the uterine expression of all the genes except HB-EGF. In addition, HB-EGF,TGF-alpha, and Areg proteins in the uterine and glandular epitheliums may participate in mid-pregnancy. Taken together, all of these activities are likely to be controlled by P4 in the uterus of pregnant rats.

Effective anatomic reconstruction of the middle hepatic vein in modified right lobe graft living donor liver transplantation

INTRODUCTION

Adult liver transplantation using the right lobe graft without a middle hepatic vein (MHV; modified right lobe graft) has widely been used to compensate for the cadaveric organ shortage. To provide appropriate functional graft volume in the right lobe graft used for living donor liver transplantation (LDLT), successful reconstruction of the MHV is required. We have described herein the effectiveness of an anatomic MHV reconstruction technique with tailoring donor hepatectomy and uniformed MHV reconstruction for modified right lobe grafts.

MATERIALS AND METHODS

From December 2005 to August 2006, 15 adult patients received modified right lobe graft LDLT using a donor hepatectomy technique that exposed the right side of the MHV combined with a bench procedure that reconstructed the modified right lobe graft into the shape of extended right lobe graft, and a modified piggyback anastomosis.

RESULTS

A total of 42 V5/V8s were reconstructed with 15 newly formed MHVs. The mean estimated congestion area was 4.2+/-2.7% of the total graft volume on computed tomography. The mean pressure gradient between the reconstructed MHV and the recipient inferior vena cava was 2.1+/-1.6 mmHg on postoperative day (POD) 7. None of the patients required any procedure for an outflow problem. The patency rates of the reconstructed MHV and its tributaries were 100% (15/15) and 95.2% (40/42), respectively, at POD 30; 100% (15/15) and 73.8% (31/42) at POD 60; and 86.7% (13/15) and 54.8% (23/42) at POD 90. All recipients are currently alive with good liver function.

CONCLUSION

Our procedure seems to be effective for the reconstruction of MHV and its tributaries, and could make modified right lobe graft into the anatomic figure of extended right lobe graft as well as achieve the physiologic advantages of an extended right lobe graft.

Fractional creatinine clearance of the donated kidney using Cockcroft-Gault formula as a predictor of graft function after living donor transplantation

To prevent hyperfiltration of the renal allograft, it is important to initially provide adequate functioning nephrons to meet the metabolic demands of a recipient. During the preoperative evaluation of a potential kidney donor, it is necessary to estimate the renal function of donated kidney compared with the metabolic needs of the recipient. The functional ratio of each kidney was measured using technetium-99m diethylenetriaminepentaacetic acid. The serum creatinine (Scr, mg/dL) and estimated creatinine clearance (Ccr, mL/min/1.73 m(2)) using the Cockcroft-Gault formula were measured and calculated in 82 donors. We excluded recipients who had an episode of rejection, and followed all recipients for more than 6 months posttransplantation. The average functional proportion of the donated kidney was 50.5% +/- 4.7% of the total Ccr 83.4 +/- 18.3 of donors. The Scr of recipients at 1, 3, 6, and 9 months posttransplantation were significantly (P < .05) correlated with the fractional Ccr of the donated kidney; however, Scr at 1 year was not correlated (P = .307). Furthermore, the Ccr of the recipient at 1, 3, and 6 months posttransplantation were significantly (P < .05) correlated with the fractional Ccr of the donated kidney; however, the Ccr at 9 months and 1 year were not correlated (P = .094 and .141, respectively). The Scr and Ccr of recipients within 6 months after transplantation may depend on the functional mass of the donated kidney, which should be estimated prior to kidney donation and compared with the metabolic demands of the potential recipient.

Preparation and drug release activity of scaffolds containing collagen and poly(caprolactone)

A new biodegradable polymeric scaffold was prepared by using collagen and poly(caprolatctone) (PCL). These scaffolds were found to be soft, spongy, and transparent in nature and characterized by thermogravimetric analysis and FTIR spectrum. To these biodegradable polymeric scaffolds, antibiotic drugs namely amikacin and gentamycin were incorporated separately to study their release pattern from scaffolds. Amikacin and gentamycin release activity of the scaffolds containing a constant quantity of collagen but different quantities of PCL were studied at various time intervals viz. 1, 4, 24, and 48 h by measuring the optical density at 257 and 255 nm, respectively.

Routine Screening for the Functional Asymmetry of Potential Kidney Donors

The functional capacity of each kidney of a healthy donor may change under the influence of genetic and environmental factors. An assumption that the donor kidneys show equal function is not always true. As part of the pre-nephrectomy evaluation of potential donors, radioisotope renal scintigraphy using technetium-99m diethylenetriaminepentaacetic acid (99mTcDTPA) was routinely included to evaluate renal functional asymmetry of undetermined etiology. The functional ratios of each kidney using 99mTcDTPA as well as serum creatinine (Scr) and creatinine clearance (Ccr) in a 24-hour urine were measured and calculated from a hundred donors. The left kidneys showed greater function (51.67%-53.35% under 95% confidence interval [CI]) and the average left versus right ratio was 52.5 versus 47.5. The average fraction of Ccr of left kidneys was 57.8 mL/min/1.73 m +/- 10.99 compared with right kidneys at 52.6 mL/min/1.73 m +/- 11.63. Seventy-three healthy volunteers donated their left kidneys, and 27, their right kidney. The average fraction of Ccr of the donated kidneys was 55.9 mL/min/1.73 m +/- 11.78 compared with that of the remnant kidneys (54.5 mL/min/1.73 m +/- 11.39). After kidney donation, the Scr of the donors increased from 0.85 mg/dL +/- 0.17 to 1.33 mg/dL +/- 0.27. The average postnephrectomy Ccr was 68.0 mL/min/1.73 m +/- 14.29. Even though the Ccr after kidney donation was higher than that of the remnant kidney estimated before the donation, one must pay attention to possible functional kidney asymmetry to select the nephrectomy site.

Effect of Basiliximab on Renal Allograft Rejection Within 1 Year After Transplantation

Basiliximab is widely used in clinical practice for initial immunosuppressive treatment of renal transplant recipients, seeking to reduce the incidence of acute rejection episodes without adverse events. This retrospective study included 123 renal allograft recipients transplanted at a single center. All were followed for longer than 1 year after transplantation and treated with calcineurin inhibitor and steroid (methylprednisolone) for prophylactic immunosuppression, but basiliximab and mycophenolate mofetil were optional. We compared the outcomes of renal transplant recipients who were versus treated were not with basiliximab as initial immunosuppressive therapy. Basiliximab was used for initial immunosuppression in 42 patients. Their maintenance immunosuppressive treatment included triple (n = 44) or double (n = 79) regimens, including a calcineurin inhibitor (cyclosporine [n = 87] or tacrolimus [n = 36]), methylprednisolone with or without mycophenolate mofetil. Twenty-six (21.1%) patients had a rejection episode within 1 year after transplantation and 22 (17.9%) had infections. Within the first year after transplantation the patients who were treated with basiliximab showed fewer rejection episodes (n = 6, 14.3%) than the patients without this therapy (n = 20, 24.7%), which was not statistically significant (P = .245). However, basiliximab significantly affected the occurrence of rejection episodes among the double immunosuppressive regimen group (P = .006), but not the triple regimen group (P = .098) without an impact on infection episodes (P value of double, triple = .291, .414) within 1 year after transplantation. We concluded that basiliximab was more useful for the recipients treated with double immunosuppression with a calcineurin inhibitor and steroid than for those on a triple regimen including mycophenolate mofetil.

Chromosome aberration and lipid peroxidation in chromium-exposed workers

Chromosome aberration frequency and lipid peroxidation levels were analyzed to investigate their efficacy as biological markers for monitoring the genotoxicity and oxidative damage in Korean chromium (Cr)-exposed workers. Fifty-one Cr-exposed workers and 31 age-matched controls in ten chrome-plating plants were sampled. The Cr level was measured in the workers' blood and urine, and in the ambient air at the workplaces. The conventional Giemsa staining method and fluorescence in situ hybridization (FISH) technique were used for chromosome aberration analysis. Spectrum green whole chromosome paint specific for chromosome 4 was used in the FISH procedure. As for lipid peroxidation, malondialdehyde (MDA) was measured in the blood plasma as thiobarbituric acid-reactive substances (TBARS). The blood Cr concentration was statistically correlated with both the frequency of chromatid exchange and the total frequency of chromosome/chromatid breaks and exchanges, as detected by the Giemsa staining. Meanwhile, the frequency of translocation, as detected by the FISH technique, was significantly higher in the Cr-exposed workers than in the controls and it correlated with the blood Cr concentration. Although the concentration of MDA, the metabolite of lipid peroxidation, in the exposed workers was higher than that of the controls, no statistically significant correlation between the MDA level and the blood or urine Cr levels was observed. Accordingly, the genotoxicity and oxidative damage (plasma lipid peroxidation) in the Korean Cr-exposed workers were consequential at quite low exposure levels, plus chromosome rearrangement, especially translocation, was clearly evident as a biological response marker for Cr exposure based on a significant positive correlation between the translocations detected by FISH and the Cr in the blood.

Bioavailability and mammary excretion of bisphenol a in Sprague-Dawley rats

This study reports the absolute oral bioavailability and mammary excretion of bisphenol A in rats. The oral bioavailability was determined after administration of relatively low iv (0.1 mg/kg) and oral (10 mg/kg) doses of bisphenol A to rats. After iv injection, serum levels of bisphenol A declined biexponentially, with the mean initial distribution and terminal elimination half-lives being 6.1 +/- 1.3 min and 52.5 +/- 2.4 min, respectively. The systemic clearance (Cls) and the steady-state volume of distribution (Vss) averaged 107.9 +/- 28.7 m/min/kg and 5.6 +/- 2.4 L/kg, respectively. Upon oral administration, the maximum serum concentration (Cmax) and the time to reach the maximum concentration (Tmax) were 14.7 +/- 10.9 ng/ml and 0.2 +/- 0.2 h, respectively. The apparent terminal elimination half-life of bisphenol A (21.3 +/- 7.4 h) after oral administration was significantly longer than that after iv injection, indicating the flip-flop of the absorption and elimination rates. The absolute oral bioavailability of bisphenol A was low (5.3 +/- 2.1%). To determine the extent of mammary excretion, bisphenol A was given by simultaneous iv bolus injection plus infusion to steady state at low, medium, and high doses. The steady-state serum levels of bisphenol A were linearly increased with higher dosing rates. The systemic clearance (mean range, 119.2-154.1 ml/min/kg) remained unaltered over the dosing rate studied. The levels of bisphenol A in milk exceeded those in serum, with the steady-state milk to serum concentration ratio being 2.4-2.7.

Protective effects of antioxidant supplementation on plasma lipid peroxidation in smokers

This study was designed to investigate the possible protective effects of antioxidants (vitamin E, beta-carotene, vitamin C, and red ginseng) on lipid peroxidation in smokers (> or = 20 cigarettes/day). Male student smokers were given antioxidant supplements for 4 wk. Smokers had significantly higher plasma levels of total cholesterol, triacylglycerols, and malondialdehyde (MDA) than nonsmokers. No corresponding significant differences in lipid profiles were found between smokers and nonsmokers. Smokers had significantly lower baseline concentrations of plasma vitamin C, beta-carotene, and alpha-tocopherol. After antioxidant (200 IU vitamin E, 9 mg beta-carotene, 500 mg vitamin C, or 1.8 g red ginseng) supplementation for 4 wk, smokers had significantly higher concentrations of plasma antioxidants. After 4 wk of antioxidant supplementation with betacarotene, high-density lipoprotein (HDL) cholesterol concentrations in smokers were significantly increased. Overall, plasma MDA concentrations gradually decreased after antioxidant supplementation over the 4-wk period. Moreover, a significant reduction in plasma MDA concentrations was observed after vitamin E supplementation. The results of our study support the hypothesis that lipid peroxidation concentrations are inversely correlated with plasma antioxidant concentrations. Our data suggest that smokers have insufficient concentrations of antioxidant vitamins in plasma and that supplementation with antioxidants might protect smokers from oxidative damage.

Potential estrogenic effects of bisphenol-A estimated by in vitro and in vivo combination assays

The potential estrogenic activities of bisphenol-A were investigated in vitro (E-screen and estrogen receptor competitive binding bioassays) and in vivo (uterotrophic assay). Uterotrophic responses were evaluated using mature ovariectomized Sprague-Dawley female rats treated subcutaneously with bisphenol A (1, 5, 10, 50, and 100 mg/kg/day), E2 (0.3 microgram/kg), and DES (0.3 microgram/kg) for 3 consecutive days. In a MCF-7 cell proliferation assay, E2 and DES used as positive estrogens induced maximum proliferation of MCF-7 cells at 1.0 nM, whereas BPA slightly induced MCF-7 cell proliferation at a higher level of 0.1 microM and maximum proliferation at 10 microM. In a competitive binding assay, E2 and DES showed inhibition of 17 beta-[3H]estradiol binding to the rat uterus ER with an IC50 of 1.0 nM and 0.5 nM, respectively. However, BPA had an IC50 of 5 microM, which was approximately 5,000 or 10,000-fold greater than the IC50 of E2 and DES. In uterotrophic assays, uterus (wet and blotted) and vagina weights were significantly increased at the dose of BPA 100 mg/kg/day in OVX Sprague-Dawley rats. These studies demonstrate that BPA exhibits weak estrogenic activity in all experimental systems, and thus its migration from epoxy resins or polycarbonate products should be controlled not to exceed a safety levels for humans.

Age-dependent skin tumorigenesis and transgene expression in the Tg.AC (v-Ha-ras) transgenic mouse

Transgenic Tg.AC (v-Ha-ras ) mice develop skin tumors in response to specific carcinogens and tumor promoters. The Tg.AC mouse carries the coding sequence of v-Ha ras, linked to a zeta-globin promoter and an SV40 polyadenylation signal sequence. The transgene confers on these mice the property of genetically initiated skin. This study examines the age-dependent sensitivity of the incidence of skin papillomas in Tg.AC mice exposed to topically applied 12-O:-tetradecanoylphorbol-13-acetate (TPA) treatment, full thickness skin wounding or UV radiation. Skin tumor incidence and multiplicity were strongly age-dependent, increasing with increasing age of the animal when first treated at 5, 10, 21 or 32 weeks of age. Furthermore, the temporal induction of transgene expression in keratinocytes isolated from TPA-treated mouse skin was also influenced by the age of the mice. Transgene expression was seen as early as 14 days after the start of TPA treatment in mice that were 10-32 weeks of age, but was not detected in similarly treated 5-week old mice. When isolated keratinocytes were fractionated by density gradient centrifugation the highest transgene expression was found in the denser basal keratinocytes. Transgene expression could be detected in the denser keratinocyte fraction as early as 9 days from start of TPA treatment in 32-week old mice. Using flow cytometry, a positive correlation was observed between expression of the v-Ha-ras transgene and enriched expression of the cell surface protein beta1-integrin, a putative marker of epidermal stem cells. This result suggests that, in the Tg.AC mouse, an age-dependent sensitivity to tumor promotion and the correlated induction of transgene expression are related to changes in cellular development in the follicular compartment of the skin.

Zinc finger proteins: new insights into structural and functional diversity

Zinc finger proteins are among the most abundant proteins in eukaryotic genomes. Their functions are extraordinarily diverse and include DNA recognition, RNA packaging, transcriptional activation, regulation of apoptosis, protein folding and assembly, and lipid binding. Zinc finger structures are as diverse as their functions. Structures have recently been reported for many new zinc finger domains with novel topologies, providing important insights into structure/function relationships. In addition, new structural studies of proteins containing the classical Cys(2)His(2) zinc finger motif have led to novel insights into mechanisms of DNA binding and to a better understanding of their broader functions in transcriptional regulation.

Protective effect of green tea extract on ischemia/reperfusion-induced brain injury in Mongolian gerbils

Free radical-induced oxidative damages of macromolecules and cell death are important factors in the pathogenesis of ischemia/reperfusion brain injury. In the present study, an investigation as to whether green tea extract reduces ischemia/reperfusion-induced brain injury in Mongolian gerbils was conducted. The effect of green tea on the ischemia/reperfusion-induced production of hydrogen peroxide, lipid peroxidation and oxidative DNA damage (formation of 8-hydroxydeoxyguanosine), and cell death in addition to locomotor activity was studied. Two doses (0.5 or 2%) of green tea extract were added into the drinking water and to be accessed by animals ad libitum for 3 weeks prior to the induction of ischemia. A global ischemia was induced by the bilateral occlusion of the common carotid arteries for 5 min. Reperfusion was achieved by releasing the occlusion and restoring blood circulation for 48 h. The infarction volumes were 112+/-31 mm(3) and 76+/-11 mm(3) in the 0.5 and 2% green tea pretreated animals compared to 189+/-12 mm(3) in the ischemia/reperfusion animals. Green tea extract also reduced the levels of ischemia/reperfusion-induced hydrogen peroxide (from 1470+/-170 to 1034+/-46 and 555+/-30 nmole/mg protein), lipid peroxidation products (from 1410+/-210 to 930+/-40 and 330+/-20 nmole/mg protein) and 8-oxodG (from 3.9+/-0.1 to 2.8+/-0.3 and1.9+/-0.3 ng/microg DNA, x10(-2)) by pretreatment of 0.5 or 2% green tea for 3 weeks, respectively. Moreover, green tea also reduced the number of ischemia/reperfusion-induced apoptotic cells (from 59+/-12 to 37+/-8, 15+/-11 apoptotic cells/high power field in the striatum region) and locomotor activity (from 15140+/-2940 to 3900+/-600 and 4100+/-1200). This study therefore suggests that green tea may be a useful agent for the prevention of cerebral ischemia damage.

Neuroprotective effect of green tea extract in experimental ischemia-reperfusion brain injury

Eicosanoids accumulation and formation of oxygen free radicals have been implicated in the pathogenesis of ischemia/reperfusion brain injury. In the present study, we examined whether green tea extract protects against ischemia/reperfusion-induced brain injury by minimizing eicosanoid accumulation and oxygen radical-induced oxidative damage in the brain. Green tea extract (0.5%) was orally administered to Wistar rats for 3 weeks before induction of ischemia. Ischemia was induced by the occlusion of middle cerebral arteries for 60 min and reperfusion was achieved for 24 h. Infarction volume in the ipsilateral hemisphere of ischemia/reperfusion animals was 114 +/- 16 mm(3) in the 0.5% green tea pretreated animals compared to 180 +/- 54 mm(3) in left hemisphere of nontreated animals. Green tea extract (0.5%) also reduced ischemia/reperfusion-induced eicosanoid concentration: Leukotriene C(4) (from 245 +/- 51 to186 +/- 22), prostoglandin E(2) (from 306 +/- 71 to 212 +/- 43) and thromboxane A(2) (327 +/- 69 to 251 +/- 87 ng/mg protein). Ischemia/reperfusion-induced increases of hydrogen peroxide level (from 688 +/- 76 to 501 +/- 99 nmole/mg protein), lipid peroxidation products (from 1010 +/- 110 to 820 +/- 70 nmole/mg protein) and 8-oxodG formation (from 1.3 +/- 0.3 to 0.8 +/- 0.2 ng/microg DNA, x10(-2)) were also reduced. Moreover, 0.5% green tea extract also reduced the apoptotic cell number (from 44 +/- 11 to 29 +/- 1 in the striatum, and from 72 +/- 11 to 42 +/- 5 apoptotic cells/high power field in the cortex region). Green tea extract pretreatment also promoted recovery from the ischemia/reperfusion-induced inhibition of active avoidance. The present study shows that the minimizing effect of green tea extract on the eicosanoid accumulation and oxidative damage in addition to the reduction of neuronal cell death could eventually result in protective effect on the ischemia/reperfusion-induced brain injury and behavior deficit.

Synthesis and Surface-Active Properties of New Photosensitive Surfactants Containing the Azobenzene Group

Several water-soluble cationic surfactants, 4-alkylazobenzene-4'-(oxy-2-hydroxypropyl)trimethylammonium methylsulfate (AZMS) (AZMS-0, AZMS-1, AZMS-2, AZMS-4, and AZMS-8), containing alkylglycidylether and azoarene have been synthesized with high yields of 63-78% and their surface-active properties have been investigated upon irradiation with UV/vis light. All of the trans-AZMS surfactants are isomerized to cis-trans mixtures containing 92.5% cis isomer by UV light irradiation at 350 nm. The cis isomers in the mixtures are reverted to trans isomers by visible light irradiation (lambda>445 nm). Such photoisomerization induces changes in the surface activity of each surfactant. The critical micelle concentration (cmc) of the trans form of AZMS-8 surfactant is about 1.28x10(-4) mol/l. At the photostationary state, 92.5% of the trans form is changed to the cis form which exhibits a slightly higher cmc (3.41x10(-4) mol/l). The new cmc of AZMS surfactants upon photoisomerization is similar to that of the ideal mixed micellar system. In particular, the ratio of cmc(cis) to cmc(trans) of AZMS derivatives is about 1.87-2.85 which increases proportionally with the chain length of alkyl group. The minimum average area per molecule (A(min)(a/w)) for the trans and cis isomers of AZMS-8 is 0.60 and 0.74 nm(2), respectively. The difference in the A(min)(a/w) may originate from the structural differences in the two isomers. These values are quite different as compared to those of the conventional azobenzene surfactants. Copyright 2000 Academic Press.

Pharmacokinetic disposition and tissue distribution of bisphenol A in rats after intravenous administration

This study examined the dose-linearity pharmacokinetics of bisphenol A, a U.S. Environmental Protection Agency (EPA) classified endocrine disruptor, in rats following iv administration. Upon iv injection of 0.2, 0.5, 1, or 2 mg/kg, serum levels of bisphenol A declined biexponentially, with mean initial distribution and elimination half-life ranges of 4-8.2 min and 38.6-62.2 min, respectively. There were no significant alterations in the systemic clearance rate (mean range 90.1-123.6 ml/min/kg) and the steady-state volume of distribution (mean range 4.6-6.0 L/kg) as a function of the administered dose. In addition, the area under the serum concentration-time curve linearly rose as the dose was increased. In a second study, bisphenol A was given by simultaneous iv bolus injection plus infusion to steady state, and levels were measured in serum and various organs. When expressed in concentration terms (e.g., amount accumulated per gram organ weight), bisphenol A was found predominantly in the lung, followed by kidneys, thyroid, stomach, heart, spleen, testes, liver, and brain. Ratios of the organ to serum bisphenol A concentrations exceeded unity for all the organs examined (ratio range 2.0-5.8) except for brain (ratio 0.75). Given the high systemic clearance and short elimination half-life, bisphenol A is unlikely to accumulate significantly in the rat.

Involvement of cortical damage in the ischemia/reperfusion-induced memory impairment of Wistar rats

The effect of ischemia/reperfusion-induced neuronal damage on the memory impairment were investigated using active avoidance and Morris water maze tasks in Wistar rats. Focal ischemia was induced by 1 h occlusion of the right middle cerebral artery (MCA) of Wistar male rats. Reperfusion was induced by releasing the occlusion and restoring the blood circulation for 24 h. The acquisition and preservation memory tested by active avoidance showed a significant difference between the sham and ischemia/reperfusion group. The water maze acquisition performance was also significant difference between sham and ischemia/reperfusion groups in both latency and moving distance. The infarction volume was increased by the ischemia/reperfusion. Furthermore, the cresyl violet staining of the ischemia/reperfusion brain showed severe neuronal damage (pyramidal cell loss) in the cortex in addition to the striatum lesion of brain. This study shows that pyramidal cell damage in the cortex lesion may be partially related to memorial disturbance in the ischemia/reperfusion brain injury.

Lipid peroxidation, antioxidant enzymes, and benzo[a]pyrene-quinones in the blood of rats treated with benzo[a]pyrene

The lipid peroxidation (as malondialdehyde, MDA), activities of superoxide dismutase (SOD) and catalase (CAT), and benzo[a]pyrene (BaP) metabolites were investigated in sera and erythrocytes of male Sprague-Dawley rats treated with BaP (20 mg per rat). MDA levels were significantly increased in sera (16.98+/-3.29 nmol/ml serum, P<0.05) 12 h after BaP treatment and persisted up to 96 h (13.80+/-1. 65 nmol/ml serum, P<0.05), but no significant change in NIDA levels was observed in erythrocytes. SOD and CAT activities were significantly increased in erythrocytes shortly after BaP exposure, and they were slightly decreased in sera, indicating an inverse correlation between lipid peroxidation and antioxidant enzyme activity. BaP and BaP-quinones (BaP-1,6-quinone and BaP-3,6-quinone) were measured in sera during the study period. A rapid increase of unmetabolized BaP was observed in sera (41.27+/-4.14 pmol/ml serum) 3 h after BaP treatment, reaching a peak at 6 h (48.56+/-4.62 pmol/ml serum) followed by a sharp decrease. Formation of the BaP-1, 6-quinone and BaP-3,6-quinone started in sera 3 h after BaP treatment, reached a peak at 24 h (7.23+/-1.02 pmol/ml serum) and 12 h (9.20+/-0.98 pmol/ml serum), respectively, and then decreased gradually. The time-dependent pattern of serum lipid peroxidation and the level of erythrocyte antioxidant enzymes were shown to be related to the concentrations of the BaP-quinone metabolites. These results suggest that BaP treatment, probably via the formation of BaP-quinones, oxidatively altered lipids and antioxidant enzymes in the blood, and might be associated with BaP-related vascular toxicity including carcinogenesis.