Cytotoxicity and absence of mutagenic activity of vomitoxin (4-deoxynivalenol) in a hepatocyte-mediated mutation assay with V79 Chinese hamster lung cells.

Cytotoxicity and mutagenicity of vomitoxin (4-deoxynivalenol), a tricothecene mycotoxin produced on cereal grains by fungi of the genus Fusarium, were determined in vitro with Chinese hamster V79 cells. Cytotoxicity was shown by a reduction in colony size at 1 microgram/ml (ppm); by reduction in the number and size of colonies at 2-3 micrograms/ml or higher; and by lethality to 80-90% of the cells at 10 micrograms/ml. Up to 3 micrograms/ml, vomitoxin was non-mutagenic to V79 cells at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus, with or without hepatocyte-mediated activation; and did not significantly increase the number of 6-thioguanine-resistant mutants at marginally cytotoxic levels of 6 and 8 micrograms/ml (data not shown). These findings, together with previous studies, suggest that vomitoxin, like other 12,13-epoxytricothecenes, may become cytotoxic through inhibition of protein and/or DNA synthesis, and is likely to be non-carcinogenic.

Lack of induction of sister chromatid exchanges and of mutation to 6-thioguanine resistance in V79 cells by butylated hydroxyanisole with and without activation by rat or hamster hepatocytes.

The antioxidant butylated hydroxyanisole (BHA) and the promutagen/carcinogen 7,12-dimethylbenz[a] anthracene (DMBA) were examined for mutagenicity and the induction of sister chromatid exchanges (SCE) in a hepatocyte-mediated mutation assay with V79 Chinese hamster lung cells. Rat and hamster hepatocytes, prepared by in situ collagenase perfusion, were compared in the mutation assay to determine whether there are species differences in the ability to activate BHA and DMBA to ultimate mutagens. At the marginally cytotoxic concentration of 1.0 microM (2.6 micrograms/ml), DMBA induced a significant increase in the frequency of SCE and in the number of mutations to 6-thioguanine resistance (6-TGR) at the hypoxanthine-guanine phosphoribosyltransferase (HGPRT) locus with either rat or hamster hepatocyte-mediated activation, but induced highest mutation frequencies with rat hepatocytes. These findings support the contention that species differences can affect mutational response in hepatocyte-mediated assays with V79 cells. BHA was strongly cytotoxic to V79 cells at dose levels in excess of 0.3 mM (54 micrograms/ml). In contrast to DMBA, BHA showed no evidence of genotoxicity at marginally cytotoxic concentrations up to and including 0.3 mM as shown by the inability of this antioxidant to increase the frequency of sister chromatid exchanges or to induce mutations to 6-thioguanine resistance when activation was provided by rat or hamster hepatocytes.

In vitro short-term testing systems as prescreens for potential carcinogens: simultaneous detection of sister chromatid exchanges and mutation response in a cell-mediated assay with V79 cells.

Sister chromatid exchange (SCE) is recognized as a sensitive indicator of genetic damage, and this has led numerous investigators to suggest that the analysis of SCE can provide a useful step toward the identification of environmental mutagens and/or carcinogens. To explore this approach, we measured SCE induction in V79 Chinese hamster lung cells and the frequency of mutation to 6-thioguanine resistance at the hypoxanthine-guanine phosphoribosyltransferase (HGPRT) locus in a cell-mediated mutation assay. Karyotypic analysis of V79 cells showed a stable modal chromosome number of 22 and an XY chromosome complement. When exposed to the procarcinogen 7,12-dimethylbenz[a]anthracene (DMBA) at marginally cytotoxic dose levels of 1.0, 0.5 and 0.25 microM (2.6, 1.3 and 0.65 micrograms/ml), SCE frequencies were highest within the first 24 h of activation with rat or hamster hepatocytes, showed somewhat lower values after 48 h of activation, and, following withdrawal of the chemical, declined to background levels during the period of expression. While this decline may involve several factors, the possibility is not excluded that DNA repair can contribute to the progressive elimination of SCE. The induction of SCE in V79 cells appeared unrelated to the expression of single-point mutation at the HGPRT locus. These findings demonstrate the advantage of multiple endpoint analysis which enabled cytotoxicity, mutagenicity and conditions optimal for the induction of SCE to be determined concurrently in a hepatocyte-mediated assay with V79 cells.

In vitro cytotoxicity of polychlorinated biphenyls (Aroclors 1016, 1242, 1254 and 1260) and their effect on phospholipid and neutral lipid composition of Chinese hamster ovary (CHO-K1) cells.

Cytotoxicity of 4 Aroclors (1016, 1242, 1254 and 1260) was compared in Chinese hamster ovary (CHO-K1) cells in Ham's F-12 medium. When parameters of toxicity were cell numbers or tissue protein, 50% lethality occurred at Aroclor concentrations between 30 and 45 ppm. An in vitro clonal assay with CHO-K1 cells was a sensitive indicator of cytotoxicity of the polychlorinated biphenyls (PCBs). From EC50 values (concentration that allowed 50% survival of formed colonies), cytotoxicity was lower with Aroclor 1016 (32 ppm) and higher with Aroclors 1254 (27 ppm) and 1260 (28 ppm). In cells exposed 24 h to a marginally cytotoxic dose (20 ppm) of each Aroclor, phospholipid (PL) thin-layer chromatography (TLC) showed an increase in phosphatidylcholine (PC) and a decrease in phosphatidylethanolamine (PE) and diphosphatidylglycerol (DPG). Neutral lipid (NL) TLC of cells given Aroclors 1242, 1254 or 1260 showed a 3-4-fold increase in triglyceride (TG) and a similar reduction in cholesteryl esters (CE); in contrast to Aroclor 1016 which produced no change in TG and a smaller (2-fold) reduction in CE. Cholesterol and free fatty acid fractions were unaffected by any of the Aroclors. The TG:PL ratio remained unchanged in cells given Aroclor 1016, but increased 3-4-fold with Aroclors 1242, 1254, or 1260. Compared to total values in the untreated controls, CHO-K1 cells contained less neutral lipid and more phospholipid only with Aroclor 1016. These results support the concept that differences in the behavior of Aroclor 1016 are related to its PCB composition. Changes in membrane PL and NL components, observed at marginally cytotoxic levels of each Aroclor, provided further evidence that the PCBs may affect membrane integrity and associated metabolic functions.

Evaluation of the genotoxicity of domoic acid in a hepatocyte-mediated assay with V79 Chinese hamster lung cells.

Domoic acid, a recognized neurotoxin derived from contaminated samples of the blue mussel (Mytilus edulis L.), was analyzed for mutagenicity at 2 loci and for 2 cytogenetic parameters in a hepatocyte-mediated assay with V79 Chinese hamster lung fibroblasts. Genetic end-points measured were: mutation to 6-thioguanine resistance at the HGPRTase locus; mutation to ouabain resistance at the Na+,K+-ATPase locus; sister-chromatid exchange (SCE) and micronucleus frequency (MN). None of these genetic end-points was significantly affected by exposure to domoic acid at dose levels of 27.2 and 54.4 micrograms/ml with or without activation by freshly isolated rat liver hepatocytes. It was concluded that, within the limits of the test system employed, domoic acid was non-genotoxic to V79 cells.

Genotoxicity of 1-nitronaphthalene in Chinese hamster V79 cells.

1-Nitronaphthalene (1-NN) has been identified in the U.S. National Toxicology Program as a non-carcinogen showing some evidence of in vitro genotoxicity. We tested this compound in Chinese hamster V79 cells at 20-80 micrograms/ml with two endpoints: sister-chromatid exchange (SCE) and thioguanine resistance (TGR), with 5 repeat experiments. The SCE values in the presence of rat or hamster hepatocytes were consistently above the 95% and usually the 99% upper confidence limits for the corresponding control. Without hepatocyte activation, the control upper confidence limits were not exceeded except in one experiment in which the control SCE value was unusually low. TGR was scored both as proportion of plates with mutant colonies and as number of mutant colonies per plate. In 2 of 5 experiments, these values exceeded control 95% or 99% upper confidence limits; on the other hand, these values were substantially lower than those of the positive controls, dimethylbenz[a]anthracene (2.6 micrograms/ml) with activation and ethyl methanesulfonate (155 microgram/ml), which is direct-acting. For TGR, activation of 1-NN by either rat or hamster hepatocytes produced inconsistent results. Overall we would consider this compound to be a weak genotoxin, to which a cancer bioassay would be expected to be relatively insensitive.

Comparative genotoxicity of 3 procarcinogens in V79 cells as related to glutathione S-transferase activity of hepatocytes from untreated rats and those fed 2% butylated hydroxyanisole.

When 7,12-dimethylbenz[a]anthracene (DMBA) and aflatoxin B1 (AFB1) were activated by hepatocytes from Fischer 344 rats fed a diet containing 2% butylated hydroxyanisole (BHA), frequencies of mutation to 6-thioguanine resistance (TGR) at the HGPRTase gene locus and to ouabain resistance (OuR) at the Na+,K(+)-ATPase gene locus in V79 cells were 30-70% less than those obtained with hepatocytes from untreated controls. A difference in the mutation frequency did not occur when dimethylnitrosamine (DMN) was activated by BHA induced- rather than control-hepatocytes. Analysis of hepatocytes from rats fed 2% BHA showed a small (1.5-fold), but significant, increase in glutathione levels over that in the controls but no change in activity of cytochrome P450. Cytosolic glutathione S-transferase (GST) activity was increased 2-3-fold in hepatocytes from rats fed the 2% BHA diet. These results suggest that mutagenic response to DMBA and AFB1 is reduced, at least in part, because of BHA-induction of hepatocyte GST activity; while activation of DMN can occur by pathway(s) unaffected by BHA-induction of these liver enzymes. In contrast to mutation frequencies, significant differences between BHA- and control-activation in the production of sister-chromatid exchange (SCE) and micronucleus formation (MN) were not detected with any of the genotoxins. It was concluded that the mechanism(s) by which SCE and MN occur are likely unrelated to the capacity of BHA to induced activity of hepatic enzymes, e.g. the GSH S-transferases, that directly or indirectly affect mutation end-points.

Evaluation of genotoxicity of tert.-butylhydroquinone in an hepatocyte-mediated assay with V79 Chinese hamster lung cells and in strain D7 of Saccharomyces cerevisiae.

tert.-Butylhydroquinone (TBHQ) has been reported to be genotoxic in some short-term assays but non-genotoxic in others. We have examined cytotoxicity and genotoxicity of TBHQ, a principal metabolite of the phenolic antioxidant 2(3)-tert.-butyl-4-hydroxyanisole (BHA), in an hepatocyte-mediated assay with V79 Chinese hamster lung cells including both sister-chromatid exchange (SCE) and thioguanine-resistance (TGR) endpoints. The ability of BHA and of TBHQ to elicit a genotoxic response in Saccharomyces cerevisiae strain D7 was also investigated. In V79 cytotoxicity tests, TBHQ without hepatocytes produced a 50% reduction in colony formation at 4.2 micrograms/ml and was lethal to 100% of the cells at concentrations above 5 micrograms/ml. At partially cytotoxic dose levels, (0.17-3.4 micrograms/ml of medium), TBHQ sometimes increased significantly the frequency of SCE. TBHQ also produced sporadic statistically significant increases in the mutation frequency at the HGPRTase (TGR) gene locus when tested alone or with activation by rat or hamster hepatocytes. Mitotic gene conversion and reverse mutation were not induced in strain D7 of Saccharomyces cerevisiae by exposure to BHA or to TBHQ for 4 h at concentrations as high as 200 micrograms/ml for BHA or 500 micrograms/ml for TBHQ, either alone or with activation by rat-liver S9. Incubation of the yeast cells with BHA or TBHQ for 24 h in growth medium without activation also did not induce genotoxic activity. The slight and sporadic response to TBHQ in the V79 test system may indicate weak genotoxicity which is sensitive to slight differences in test conditions. The classification and test strategies adopted for compounds such as TBHQ could have important implications for regulatory decisions and for the validation of short-term tests.

A statistical evaluation of the reproducibility of micronucleus, sister-chromatid exchange, thioguanine-resistance and ouabain-resistance assays in V79 cells exposed to ethyl methanesulfonate and 7,12-dimethylbenz[a]anthracene.

In contrast to the "validation" of short-term in vitro genotoxicity assays by concordance with the rodent cancer bioassay, the present report describes the multiple replication of 4 short-term tests with V79 cells (micronucleus assay, MN; sister-chromatid exchange, SCE; ouabain resistance. OUR; and thioguanine resistance, TGR) within the same assay system following exposure to each of two genotoxins, ethyl methanesulfonate (direct acting) and 7,12-dimethylbenz[a]anthracene (indirect acting). Reproducibility, proportion of genotoxins correctly identified, and proportion of non-genotoxins correctly identified by each test were each determined statistically. Decision rules were formulated to declare a positive response in each assay, and overall accuracy of each was determined. Statistical analysis of the data, obtained under standardized test conditions, showed that for these two chemicals SCE identified 100% of genotoxins and 86% of non-genotoxins, with overall accuracy of prediction of 93%; TGR identified 98% of genotoxins and 74% of non-genotoxins, with overall accuracy of 86%; MN identified 78% of genotoxins and 84% of non-genotoxins, with overall accuracy of 81%; while OUR indicated 100% of genotoxins, but only 50% of non-genotoxins, and only 76% overall accuracy. The results suggested that the best overall accuracy of classification with the V79 assay system could be achieved by measurement of SCE in combination with thioguanine resistance.

Evaluation of genotoxicity of N-nitrosodibenzylamine in Chinese hamster V79 cells and in Salmonella.

Health concerns have arisen due to the formation of N-nitrosodibenzylamine (NDBzA; CAS No. 5336-53-8) in pork processed in a new type of rubber netting. In view of the potent carcinogenicity of related nitrosamines (e.g. N-nitroso-n-dibutylamine and N-nitrosodiethylamine), NDBzA was evaluated for genotoxicity in vitro in both Chinese hamster V79 cells and in Salmonella. In V79 cells, concentrations up to 25 micrograms/ml were tested with and without activation by rat or hamster hepatocytes. Significant elevation of SCE frequency was seen only at 25 micrograms/ml in the presence of uninduced hamster hepatocytes. Mutation to 6-thioguanine resistance was observed at 25 micrograms/ml, in the absence of hepatocytes and in the presence of induced (Aroclor 1254) or uninduced hamster hepatocytes, but not with rat hepatocytes. With uninduced rat hepatocytes, a small but significant (p less than 0.05) increase in the mutation frequency was seen with 10 micrograms/ml NDBzA. In the Salmonella assay, using a pre-incubation protocol and concentrations up to 1000 micrograms/ml, NDBzA was negative in strain TA98, and in TA100 with rat S9, but was positive at the highest dose in TA100 with hamster S9, and more strongly with Aroclor 1254-induced hamster S9. When activated by uninduced rat or hamster hepatocytes, as opposed to S9, NDBzA was negative with all tester strains. Hamster hepatocytes activated more than rat in the V79 studies, and hamster S9 was more strongly activating in the Salmonella assay. These results indicate that NDBzA is weakly mutagenic to both Salmonella and V79 cells.

A multiple end-point approach to evaluation of cytotoxicity and genotoxicity of erythrosine (FD and C Red No. 3) in a V79 hepatocyte-mediated mutation assay.

V79 Chinese hamster lung cells were used to evaluate in vitro the cytotoxicity and genotoxicity of erythrosine (2', 4', 5', 7'-tetraiodofluorescein disodium salt; FD and C Red No. 3), a color additive used widely in foods, drugs and cosmetics. Erythrosine reduced colony size at 200 micrograms/ml and was lethal to 90% or more of the cells at 400 micrograms/ml. At dose levels of 100, 200 and 300 micrograms/ml of medium, erythrosine was non-mutagenic to V79 cells at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) and sodium, potassium ATPase (Na+, K+ -ATPase) gene loci and did not increase the frequency of sister-chromatid exchanges with or without rat hepatocyte-mediated activation. Erythrosine at 300 micrograms/ml, unlike lower dose levels, produced an increase in micronucleus frequency in the absence of hepatocytes. An erythrosine dose-related increase in the mitotic frequency was due to an increase in the number of first mitoses at the expense of later cell divisions. Hepatocytes moderated the effect of erythrosine treatment on micronucleus frequency, mitotic frequency and MII/MI ratio. These results demonstrate the advantage of a multiple end-point approach to the evaluation of cytotoxicity and genotoxicity within a single-assay system.

Cytotoxic and genotoxic properties of tert.-butyl-p-quinone (TBQ) in an in vitro assay system with Chinese hamster V79 cells and in strain D7 of Saccharomyces cerevisiae.

tert.-Butyl-p-quinone (TBQ), a major metabolite of the phenolic antioxidant tert.-butyl-4-hydroxyanisole (BHA), was examined for cytotoxic and genotoxic properties in an in vitro assay system with Chinese hamster V79 cells and in diploid strain D7 of Saccharomyces cerevisiae. TBQ was prepared from BHA by oxidative demethylation with sodium nitrite at low pH. Spectroscopic analyses identified the crystalline reaction product as TBQ with a purity close to 100%. Cytotoxicity of TBQ was determined by cloning efficiency in the absence of hepatocyte activation. TBQ reduced colony size of V79 cells at 0.4 micrograms/ml, prevented growth of 50% of the cells at 0.6 micrograms/ml, and was lethal to 100% of the cells at concentrations above 1.0 micrograms/ml. TBQ was 6-7 times more cytotoxic to V79 cells than TBHQ, a related BHA metabolite, and 100 times more cytotoxic than BHA. At dose levels of 0.2, 0.4 and 0.6 micrograms/ml of medium, TBQ did not increase significantly the frequency of sister-chromatid exchanges (SCE) in V79 cells and did not consistently increase the frequency of mutation to thioguanine resistance (TGR) at the hgprt gene locus either alone or with activation by rat hepatocytes. Incubation with TBQ for 4 h at pH 3.6 without activation resulted in only small increases in the frequency of gene conversion and reverse mutation in strain D7 of Saccharomyces cerevisiae. However, exposure to TBQ alone in growth medium for 24 h, produced inconsistent results. From these studies it was concluded that TBQ was cytotoxic but not genotoxic to V79 cells; and may be weakly genotoxic to strain D7 of S. cerevisiae.

Neonatal neurologic characteristics of preterm twin infants <1,250 gm birth weight.

The study objectives were to determine the incidence, time of onset, and clinical characteristics of neonatal neurologic injury in preterm twin infants <1,250 gm birth weight. Forty-one twin infants of birth weight 929 gm +/- 160 and 27.3 +/- 1.96 weeks gestation were evaluated and compared to 225 singleton infants <1,250 gm. Seventeen infants were monozygotic and 24 dizygotic. Six of the 9 monozygotic pregnancies were complicated by the polyhydramnios/oligohydramnios syndrome; a weight discordancy of >20% was observed in 8 of the monozygotic twin sets and polycythemia (hematocrit >65%) in 3 infants. Nine (22%) of the 41 infants died. Periventricular-intraventricular hemorrhage (PV-IVH) developed in 11 (27%) of 41 infants and was severe in 9 (22%) infants. IVH was noted on day 1 (n = 2), day 2 (n = 3), and day 3 (n = 6). IVH developed in 69 (30%) of the 225 singletons and was severe in 28 (12%) infants. Twin infants were more likely to have been delivered via cesarean section, to have required intubation in the delivery room, and to have been administered surfactant as compared with singletons (P < .01). It was concluded that preterm twin infants <1,250 gm are at high risk for developing severe IVH, and that the onset of IVH was within the first 3 postnatal days in all cases.

Linear hyperechogenicity within the basal ganglia and thalamus of preterm infants.

Linear hyperechogenicity (LHE) within the basal ganglia and thalamus is an uncommon sonographic finding in preterm infants and is of unclear significance. The study objectives were to determine the clinical characteristics and neurodevelopmental outcome in preterm infants who develop LHE. Ten preterm and 20 control infants were evaluated developmentally at 18 months adjusted age using the Bayley Scales of Infant Development. LHE was diagnosed at 4 weeks (range = 1-11). Antenatal glucocorticoid therapy was more common in infants with LHE than in the control infants (90% vs 45%). Four (44%) of nine LHE infants and no control infants were positive for cytomegalovirus (P = 0.02, and three of 10 LHE infants and no control infants had a hypothyroid (P = 0.03). The mental development scores and behavioral evaluation results were lower in the infants with LHE than in the control infants (73.7 +/- 9.7 vs 83.7 +/- 9.4, P = 0.01 and 23.7 +/- 20.1 vs 43.9 +/- 25.4, P = 0.04, respectively). The infants without LHE also had poorer motor quality (22.8 +/- 20. 5 vs 55.7 +/- 37.4, P = 0.02) and lower emotional regulation scores (25.7 +/- 16 vs 42.3 +/- 24, P = 0.06) than the control infants. Preterm infants with LHE are at an increased risk of adverse neurodevelopmental outcome and, in particular, cognitive and behavioral performance. The sonographic evolution of LHE may be a marker of a diffuse insult to the brain.

Evaluation of cytotoxicity and genotoxicity of okadaic acid, a non-phorbol ester type tumour promoter, in V79 Chinese hamster lung cells.

Okadaic acid, a specific phosphatase inhibitor and non-phorbol ester type tumour promoter, was examined for cytotoxic and genotoxic properties in a hepatocyte-mediated assay with V79 Chinese hamster lung fibroblasts. Genetic endpoints measured were: mutation to 6-thioguanine resistance at the hgprt gene locus and induction of sister chromatid exchange (SCE). The cytotoxicity of okadaic acid to V79 cells was determined in the absence of hepatocytes at concentrations from 0 to 30 ng/ml medium. Okadaic acid decreased colony size at 20 ng/ml, reduced colony formation by 50% (LC(50)) at 24 ng/ml, and was lethal to 100% of the cells at concentrations above 30 ng/ml. Exposure of V79 cells to okadaic acid for as little as 24 hr without hepatocytes invoked morphological changes that were concentration related. By comparison, okadaic acid was less able to invoke changes in morphology of V79 cells when co-cultivated with rat hepatocytes, but did alter hepatocyte morphology. In genotoxicity tests, mutation frequencies were increased signficantly by okadaic acid only in the absence of hepatocytes and only at the highest tested concentration (20 ng/ml medium). In contrast, SCE frequencies were not affected when okadaic acid was tested alone or with hepatocyte activation at concentrations as high as 20 ng/ml. It was concluded that, within the limits of the test system used, okadaic acid was strongly cytotoxic and may function as a direct-acting mutagen, but was otherwise without cytogenetic activity towards V79 cells.

Toxicity of structurally related anthraquinones and anthrones to mammalian cells in vitro.

Anthraquinones and structurally related compounds were cytotoxic to mammalian cell lines using cloning efficiency and MTT reduction as endpoints. In V79 cells, the concentration of chemical causing 50% inhibition ranged from 0.21 to 21.6 mug/ml for cloning efficiency and from 0.86 to 14.6 mug/ml for MTT reduction. The anthrones anthralin and chrysarobin were 4.1 and 3.2 times more toxic, respectively, in the cloning efficiency assay than in the MTT assay. In contrast, the anthraquinones danthron and emodin were 2.8 and 2.1 times more toxic, respectively, in the MTT assay than in the cloning efficiency assay. Among the four mammalian cell lines tested using the MTT assay, the human leukaemia cell line (K562) was the most sensitive to the test chemicals. In contast, anthraquinone toxicity was reduced in rat hepatoma (H4IIE) cultures. In general, structures with carbonyl groups in positions 9 and 10 on the anthracene skeleton (anthraquinones) were less toxic than structures with carbonyl groups in position 9 only (anthrones). Toxicity was also influenced by the position of hydroxy substituents on the tricyclic skeleton. The results suggested that in vitro cytotoxicity assays are useful in elucidating the relationships between structure and biological activity for anthraquinones and related compounds.

Intrahepatic vascular shunting for portal hypertension: early experience with the transjugular intrahepatic porto-systemic shunt.

The treatment of patients with portal hypertension and hemorrhaging varices remains an enigma within the surgeon's world. Many procedures have been described, which suggests that no general consensus exists regarding the proper care for these individuals. Also, these procedures usually lead to massive blood use and exposure to patients who have had multiple blood transfusions, thus posing an extreme infectious risk to the surgical team. Eight patients refractory to repeated esophageal sclerotherapy with advanced portal hypertension underwent the transjugular intrahepatic portosystemic shunt (TIPS) procedure. One other patient with altered anatomy underwent transjugular porto-caval shunt (TPCS) procedure via the caudate lobe of the liver. All procedures were successful in stopping esophageal hemorrhage within 6 hours of shunting. The portal-hepatic vein pressure gradient pre-shunt averaged 20 mm Hg, and post-shunt averaged 11 mm Hg. Two patients developed encephalopathy, which was controlled with medication and/or diet modifications. Three patients classified as Child's C-plus died within 1 week of their shunting procedure, and one patient, who had received greater than 60 units of blood, within 10 days pre-shunt, died 45 days post-shunt of multi-system organ failure. Four of the original nine patients are now classified as Child's A with active lives, eligible for transplantation without altered abdominal anatomy. The follow-up period is from 5 to 11 months. TIPS and TPCS are methods that should be considered the front-line invasive management techniques for patients with portal hypertension who have failed esophageal sclerotherapy.

Erucic acid and phospholipids of newborn rat heart cells in culture.

Erucic acid (delta 13-docosenoic acid), labeled with 14C in the 1- or 14-position, was incorporated into fetal calf serum and fed to beating, neonatal rat myocardial cell in culture. Uptake of the docosenoic acid during the first 6 hr of incubation was 41 nM/hr/mg protein in 7-day old cells and 29 nM/hr/mg protein in 14-day old cells. Fifty-seven percent of the 14C-activity was taken up from the medium in 24 hr, of which 77% was in the cells and 23% was unaccounted for. Of the 14C-activity taken up, 26% was in extractable lipid, with two-thirds in neutral lipid and one-third in phospholipid. Within the neutral lipid fraction, 88% of the 14C-activity was present in triglycerides; while in phospholipids, 66% of the 14C-activity was in phosphatidylcholine (PC); 14% in phosphatidylethanolamine (PE); 6% in sphinogomyelin (SPH) and 1% or less in cardiolipin (DPG). PC had the highest specific activity, followed by SPH and PE. The specific activity of PE was one-half that of SPH when the 14C-erucic acid substrate was labeled at the carboxyl position, but increased to equal that of SPH when the substrate was labeled at the double bond. The fatty acids of PC, PE, and SPH were influenced by erucic acid in the growth medium, but the amounts of each phospholipid were not affected. It is proposed that the altered fatty acid composition associated with incorporation of erucic acid or its metabolites into PC, PE, and SPH may affect integrity and function of heart cell membranes.

Gender differences in motivational style: a comparison of measures and curriculum area.

BACKGROUND: Gender has long been implicated in school-based performance with gender differences varying across curriculum domains. Motivational differences have often been cited as a possible cause. However, evidence for the pattern of motivational difference between the genders is unclear. AIMS: This study compares the motivational responses of girls and boys in the curriculum areas of mathematics and English. Two different measures of motivation are employed. SAMPLES: The sample consists of all pupils from years 7, 9 and 11 in two secondary schools in Northern England. A total of 435 yr 7, 389 yr 9 and 357 yr 11 students was available. METHODS: Students completed two assessments of motivation, one based on self-report measures of goal strength and the other on performance over four tasks. Some school performance data were also available. RESULTS: The two motivation measures produce different patterns of results. The task-based measure shows no gender based differences while the other indicates a pattern of differences broadly suggestive of an advantage for girls. CONCLUSIONS: Future exploration of gender effects in motivation needs to give careful consideration to the type of motivation under consideration. Univariate models are unlikely to be adequate.