Ramucirumab with cisplatin and fluoropyrimidine as first-line therapy in patients with metastatic gastric or junctional adenocarcinoma (RAINFALL): a double-blind, randomised, placebo-controlled, phase 3 trial

BACKGROUND

VEGF and VEGF receptor 2 (VEGFR-2)-mediated signalling and angiogenesis can contribute to the pathogenesis and progression of gastric cancer. We aimed to assess whether the addition of ramucirumab, a VEGFR-2 antagonist monoclonal antibody, to first-line chemotherapy improves outcomes in patients with metastatic gastric or gastro-oesophageal junction adenocarcinoma.

METHODS

For this double-blind, randomised, placebo-controlled, phase 3 trial done at 126 centres in 20 countries, we recruited patients aged 18 years or older with metastatic, HER2-negative gastric or gastro-oesophageal junction adenocarcinoma, an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and adequate organ function. Eligible patients were randomly assigned (1:1) with an interactive web response system to receive cisplatin (80 mg/m2, on the first day) plus capecitabine (1000 mg/m2, twice daily for 14 days), every 21 days, and either ramucirumab (8 mg/kg) or placebo on days 1 and 8, every 21 days. 5-Fluorouracil (800 mg/m2 intravenous infusion on days 1-5) was permitted in patients unable to take capecitabine. The primary endpoint was investigator-assessed progression-free survival, analysed by intention to treat in the first 508 patients. We did a sensitivity analysis of the primary endpoint, including a central review of CT scans. Overall survival was a key secondary endpoint. This study is registered with ClinicalTrials.gov, number NCT02314117.

FINDINGS

Between Jan 28, 2015, and Sept 16, 2016, 645 patients were randomly assigned to receive ramucirumab plus fluoropyrimidine and cisplatin (n=326) or placebo plus fluoropyrimidine and cisplatin (n=319). Investigator-assessed progression-free survival was significantly longer in the ramucirumab group than the placebo group (hazard ratio [HR] 0·753, 95% CI 0·607-0·935, p=0·0106; median progression-free survival 5·7 months [5·5-6·5] vs 5·4 months [4·5-5·7]). A sensitivity analysis based on central independent review of the radiological images did not corroborate the investigator-assessed difference in progression-free survival (HR 0·961, 95% CI 0·768-1·203, p=0·74). There was no difference in overall survival between groups (0·962, 0·801-1·156, p=0·6757; median overall survival 11·2 months [9·9-11·9] in the ramucirumab group vs 10·7 months [9·5-11·9] in the placebo group). The most common grade 3-4 adverse events were neutropenia (85 [26%] of 323 patients in the ramucirumab group vs 85 [27%] of 315 in the placebo group), anaemia (39 [12%] vs 44 [14%]), and hypertension (32 [10%] vs 5 [2%]). The incidence of any-grade serious adverse events was 160 (50%) of 323 patients in the ramucirumab group and 149 (47%) of 315 patients in the placebo group. The most common serious adverse events were vomiting (14 [4%] in the ramucirumab group vs 21 [7%] in the placebo group) and diarrhoea (11 [3%] vs 19 [6%]). There were seven deaths in each group, either during study treatment or within 30 days of discontinuing study treatment, which were the result of treatment-related adverse events. In the ramucirumab group, these adverse events were acute kidney injury, cardiac arrest, gastric haemorrhage, peritonitis, pneumothorax, septic shock, and sudden death (n=1 of each). In the placebo group, these adverse events were cerebrovascular accident (n=1), multiple organ dysfunction syndrome (n=2), pulmonary embolism (n=2), sepsis (n=1), and small intestine perforation (n=1).

INTERPRETATION

Although the primary analysis for progression-free survival was statistically significant, this outcome was not confirmed in a sensitivity analysis of progression-free survival by central independent review, and did not improve overall survival. Therefore, the addition of ramucirumab to cisplatin plus fluoropyrimidine chemotherapy is not recommended as first-line treatment for this patient population.

FUNDING

Eli Lilly and Company.

Olaparib Versus Nonplatinum Chemotherapy in Patients With Platinum-Sensitive Relapsed Ovarian Cancer and a Germline BRCA1/2 Mutation (SOLO3): A Randomized Phase III Trial

PURPOSE

A phase II study (ClinicalTrials.gov identifier: NCT00628251) showed activity of olaparib capsules versus pegylated liposomal doxorubicin in patients with germline BRCA-mutated platinum-resistant or partially platinum-sensitive relapsed ovarian cancer. We conducted a phase III trial (SOLO3) of olaparib tablets versus nonplatinum chemotherapy in patients with germline BRCA-mutated platinum-sensitive relapsed ovarian cancer who had received at least 2 prior lines of platinum-based chemotherapy.

PATIENTS AND METHODS

In this randomized, open-label trial, patients were randomly assigned 2:1 to olaparib 300 mg twice a day or physician's choice single-agent nonplatinum chemotherapy (pegylated liposomal doxorubicin, paclitaxel, gemcitabine, or topotecan). The primary end point was objective response rate (ORR) in the measurable disease analysis set assessed by blinded independent central review (BICR). The key secondary end point was progression-free survival (PFS) assessed by BICR in the intent-to-treat population.

RESULTS

Of 266 randomly assigned patients, 178 were assigned to olaparib and 88 to chemotherapy. In patients with measurable disease (olaparib, n = 151; chemotherapy, n = 72), the BICR-assessed ORR was significantly higher with olaparib than with chemotherapy (72.2% v 51.4%; odds ratio [OR], 2.53 [95% CI, 1.40 to 4.58]; P = .002). In the subgroup who had received 2 prior lines of treatment, the ORR was 84.6% with olaparib and 61.5% with chemotherapy (OR, 3.44 [95% CI, 1.42 to 8.54]). BICR-assessed PFS also significantly favored olaparib versus chemotherapy (hazard ratio, 0.62 [95% CI, 0.43 to 0.91]; P = .013; median, 13.4 v 9.2 months). Adverse events were consistent with the established safety profiles of olaparib and chemotherapy.

CONCLUSION

Olaparib resulted in statistically significant and clinically relevant improvements in ORR and PFS compared with nonplatinum chemotherapy in patients with germline BRCA-mutated platinum-sensitive relapsed ovarian cancer who had received at least 2 prior lines of platinum-based chemotherapy.

Chemical mutagenesis testing in Drosophila. V. Results of 53 coded compounds tested for the National Toxicology Program

Fifty-three chemicals were tested for mutagenicity in Drosophila melanogaster by adult feeding and, where results were negative, by adult injection for the induction of sex-linked recessive lethal mutations in meiotic and postmeiotic germ cell stages of Canton-S males. One compound was tested by inhalation. Those compounds that induced lethal mutations were tested further for the induction of reciprocal translocations. Seventeen of the 53 compounds (acetaldehyde, 2-aminoanthracene, bromoform, t-butyl hydroperoxide, chlorambucil, trans-cinnamaldehyde, crotonaldehyde, 1,3-dichloro-5,5-dimethylhydantoin, 3,4-dichloronitrobenzene, dimethoxane, 2,4-dinitrotoluene, 1,2-epoxy-3,3,3-trichloropropane, formaldehyde, furfural, halothane, HC yellow 4, and picric acid) were found to induce lethal mutations and three (2-aminoanthracene, chlorambucil,and crotonaldehyde) also induced reciprocal translocations.

The sex-linked recessive lethal test for mutagenesis in Drosophila melanogaster. A report of the U.S. Environmental Protection Agency Gene-Tox Program

The test for sex-linked recessive lethals (SLRL) in Drosophila melanogaster has been used to detect induced mutations since 1927. The advantage of the test for both screening and hazard evaluation is its objectivity in testing for transmissible mutations in the germ cells of a eukaryote. Statistical criteria for both positive and negative mutagenicity at the highest concentration tested under a particular exposure condition were developed by the Work Group, and a recommended protocol for future testing was agreed upon. For 421 compounds there were sufficient data available in the literature for analysis; 198 compounds were found to be positive and 46 negative at the highest concentration tested. Most experiments had been done for objectives of pure research rather than for deliberately screening for mutagenicity, although many of the 421 chemicals were selected for testing because of suspected mutagenicity. Therefore, the statement of 198 positive and 46 negative should not be taken as an example of the proportion of mutagens in the environment. In three sets of experiments with D. melanogaster that were done specifically for screening, one involving 40 compounds for the Environmental Protection Agency (EPA), the others involving 13 for the Food and Drug Administration (FDA), only 6 mutagens were discovered. After completion of the classification of compounds according to their response in the SLRL test, the compounds were classified as to their carcinogenic response according to the list of Griesemer and Cueto (1980). There were 62 compounds that could be classified as positive or negative for both carcinogenesis and mutagenesis. Of the 62 compounds, there was agreement between the carcinogenesis and mutagenesis classification in 56 (50 positive and 6 negative), or 90% would have been correctly classified as to carcinogenesis from only the SLRL test. Because of inadequate sample size, 177 compounds could not be classified as positive or negative according to the statistical criteria established by the Work Group. This large number of inadequately tested compounds reflects the fact that many of the experiments were not done for screening. Further work is needed on the compounds with inadequate sample size.(ABSTRACT TRUNCATED AT 400 WORDS)

Chemical mutagenesis testing in Drosophila. IV. Results of 45 coded compounds tested for the National Toxicology Program

Results from Drosophila mutagenicity tests of 45 chemical compounds assayed for the National Toxicology Program are presented. Nine compounds were judged positive and four equivocal in the sex-linked recessive lethal test. The nine positive compounds were acetin, allyl glycidyl ether, cyclophosphamide, 1,2-dibromo-3-chloropropane, 2,3-dibromo-1-propanol, dimethylcarbamyl chloride, 1,2-epoxy-butane, lasiocarpine, and N-nitrosopiperidine. The results for chloral hydrate, maleic hydrazide, propantheline bromide, and trifluralin were equivocal. Of the nine compounds positive in recessive lethal induction, only two--allyl glycidyl ether and dimethylcarbamyl chloride--failed to induce translocations. The remaining 32 were judged to be nonmutagenic under the conditions used.

Distribution of C-reactive protein and its relation to risk factors and coronary heart disease risk estimation in the National Health and Nutrition Examination Survey (NHANES) III

The authors examined the distribution of, and risk factors associated with, the inflammatory marker C-reactive protein (CRP) among a large sample of non-institutionalized American adults aged 30-74 years of age, and its relation to estimated 10-year coronary heart disease risk. The population studied comprised 4472 men and 5212 women aged 30-74 years, without coronary heart disease, who had CRP measurements in the Third National Health and Nutrition Examination Survey (NHANES III). The 10-year risk of coronary heart disease was estimated from Framingham risk factor algorithms among those with CRP levels of less-than-or-equal0.21 mg/dL, >0.21 to <0.5mg/dL, 0.5 to <1.0 mg/dL, and greater-than-or-equal1.0 mg/dL. Mean (SD) levels of CRP were 0.41 (0.64) mg/dL in men and 0.55 (0.91) mg/dL in women. Levels of at least 1 mg/dL were measured in 6.4% of men and 12.9% of women. CRP levels were highest among non-Hispanic black men and Mexican-American women. According to multiple logistic regression analysis, cigarette smoking and increased age, body mass index, and systolic blood pressure in men, and body mass index and diabetes in women, were strongly associated with a greater likelihood of CRP levels of greater-than-or-equal1.0 mg/dL (p<0.001). Among persons with CRP levels of less-than-or-equal0.21 mg/dL, >0.21 to <0.5 mg/dL, 0.5 to <1.0 mg/dL and greater-than-or-equal1.0 mg/dL, the 10-year estimated risk of coronary heart disease were 13.4%, 17.6%, 19.6%, and 21.1% among men, respectively, and 2.7%, 3.6%, 4.1% and 4.3% among women, respectively (both p<0.001 across CRP categories); higher risks across CRP groups were also found among ethnic/gender subgroups. CRP remained a significant predictor of coronary heart disease risk in unadjusted and age-adjusted analyses. Conclusion. Elevation of CRP is associated with several major coronary heart disease risk factors and with unadjusted and age-adjusted projections of 10-year coronary heart disease risk in both men and women. (c)2001 CHF, Inc. Presented at the Fifth International Conference on Preventive Cardiology, Osaka, Japan, May, 2001.

Chemical mutagenesis testing in Drosophila. III. Results of 48 coded compounds tested for the National Toxicology Program

Forty-eight chemicals were tested for mutagenicity in Drosophila melanogaster. Each compound was tested first for the induction of sex-linked recessive lethals (SLRLs) by feeding the chemical in a solution of 5% aqueous sucrose. If it was not mutagenic by this route, the chemical was tested by injection in a solution of 0.7% aqueous NaCl. If found inactive, the compound was not tested further. If it was mutagenic, the compound was tested for the induction of reciprocal translocations (RTs) using the exposure protocol and germ cell stage that yielded positive results in the SLRL assay. Eight chemicals (diglycidylresorcinol ether, AF-2, alloxan monohydrate, 1-aziridine ethanol, p,p'-DDE, dichloroacetonitrile, 1,3-dichloropropene, and 3,3'-dimethylbenzidine dihydrochloride) were found to induce SLRLs. Only diglycidylresorcinol ether also induced RTs.

Chemical mutagenesis testing in Drosophila. X. Results of 70 coded chemicals tested for the National Toxicology Program

Seventy chemicals were tested for the ability to induce sex-linked recessive lethal (SLRL) mutations in postmeiotic and meiotic germ cells of male Drosophila melanogaster. As in the previous studies in this series, adult feeding was chosen as the first route of administration. If the compound failed to induce mutations by this route, injection exposure was used. Two chemicals, n-butane and propylene, were gaseous and therefore tested only by inhalation. One chemical (dimethylcarbamoyl chloride) was tested only by injection. Those chemicals that were mutagenic in the SLRL assay were further tested for the ability to induce reciprocal translocations. Sixteen of the 70 chemicals tested were mutagenic in the SLRL assay: 3-chloro-2-methylpropene, 3-(chloromethyl)pyridine HCl, dimethylcarbamoyl chloride, HC blue 1,3-iodo-1,2-propanediol, malaoxon, N,N'-methylene-bis-acrylamide, 4,4'-methylenedianiline 2HCl, ziram, cis-dichlorodiaminoplatinum II, 1,2-dibromoethane, dibromomannitol, 1,2-epoxypropane, glycidol, myleran, and toluene diisocyanate. The last seven also induced reciprocal translocations. A comparison of the results from the SLRL assay with other assays for mutagens and carcinogens suggests that the SLRL assay is highly specific, but poorly sensitive, both for mutagens and potential carcinogens.

Living at the Frontiers of Life: Extremophiles in Chile and Their Potential for Bioremediation

Extremophiles are organisms capable of adjust, survive or thrive in hostile habitats that were previously thought to be adverse or lethal for life. Chile gathers a wide range of extreme environments: salars, geothermal springs, and geysers located at Altiplano and Atacama Desert, salars and cold mountains in Central Chile, and ice fields, cold lakes and fjords, and geothermal sites in Patagonia and Antarctica. The aims of this review are to describe extremophiles that inhabit main extreme biotopes in Chile, and their molecular and physiological capabilities that may be advantageous for bioremediation processes. After briefly describing the main ecological niches of extremophiles along Chilean territory, this review is focused on the microbial diversity and composition of these biotopes microbiomes. Extremophiles have been isolated in diverse zones in Chile that possess extreme conditions such as Altiplano, Atacama Desert, Central Chile, Patagonia, and Antarctica. Interesting extremophiles from Chile with potential biotechnological applications include thermophiles (e.g., Methanofollis tationis from Tatio Geyser), acidophiles (e.g., Acidithiobacillus ferrooxidans, Leptospirillum ferriphilum from Atacama Desert and Central Chile copper ores), halophiles (e.g., Shewanella sp. Asc-3 from Altiplano, Streptomyces sp. HKF-8 from Patagonia), alkaliphiles (Exiguobacterium sp. SH31 from Altiplano), xerotolerant bacteria (S. atacamensis from Atacama Desert), UV- and Gamma-resistant bacteria (Deinococcus peraridilitoris from Atacama Desert) and psychrophiles (e.g., Pseudomonas putida ATH-43 from Antarctica). The molecular and physiological properties of diverse extremophiles from Chile and their application in bioremediation or waste treatments are further discussed. Interestingly, the remarkable adaptative capabilities of extremophiles convert them into an attractive source of catalysts for bioremediation and industrial processes.

Chemical mutagenesis testing in Drosophila. II. Results of 20 coded compounds tested for the National Toxicology Program

Results are presented from mutagenesis testing in Drosophila of 20 coded compounds. Two compounds were positive in the sex-linked recessive lethal test, and two were inconclusive. The positive compounds were calcium chromate in adult feeding experiments and ferrocene after adult injection. The two inconclusive compounds were 2,4-diaminophenol dihydrochloride and hexachlorocyclopentadiene. Compounds that produced a positive response were assayed for chromosome breakage using the conventional translocation test. Calcium chromate was negative in the translocation test, and ferrocene was positive. Many of the test compounds were poorly soluble in water, raising questions regarding the effective concentration to which the flies were exposed.

An overview of short-term tests for the mutagenic and carcinogenic potential of pesticides

In the last few years, marked progress has been made in the development of methods for evaluating the mutagenic and carcinogenic potential of pesticide chemicals. The correlation of genetic and related biological activity in short-term tests with carcinogenic activity in whole animals allows the utilization of short-term mutagenicity bioassays to prescreen chemicals for effects related to mutation induction and presumptive carcinogenicity. In addition, bioassays now available can measure directly the chemical transformation of normal cells in culture into cells capable of producing tumors when injected into animals. This paper will review briefly the major types of relevant short-term tests and will develop a rationale for a phased approach to the evaluation of the mutagenic and carcinogenic potential of environmental chemicals. This approach involves the sequential application of bioassays which are organized into a three-level matrix emphasizing first detection, then confirmation, and finally hazard assessment. Chemicals demonstrating positive results in the short-term detection systems and confirmatory bioassays are pursued in higher level whole animal define a negative result. The phased approach should facilitate a cost effective utilization of limited testing resources and provide protection for human health in proportion to the anticipated hazard. Results obtained in evaluating a series of thirty-eight pesticide chemicals according to the phased approach discussed in detail.

Habitat filtering across tree life stages in tropical forest communities

Tropical tree communities are shaped by local-scale habitat heterogeneity in the form of topographic and edaphic variation, but the life-history stage at which habitat associations develop remains poorly understood. This is due, in part, to the fact that previous studies have not accounted for the widely disparate sample sizes (number of stems) that result when trees are divided into size classes. We demonstrate that the observed habitat structuring of a community is directly related to the number of individuals in the community. We then compare the relative importance of habitat heterogeneity to tree community structure for saplings, juveniles and adult trees within seven large (24-50 ha) tropical forest dynamics plots while controlling for sample size. Changes in habitat structuring through tree life stages were small and inconsistent among life stages and study sites. Where found, these differences were an order of magnitude smaller than the findings of previous studies that did not control for sample size. Moreover, community structure and composition were very similar among tree sub-communities of different life stages. We conclude that the structure of these tropical tree communities is established by the time trees are large enough to be included in the census (1 cm diameter at breast height), which indicates that habitat filtering occurs during earlier life stages.

Multispecies coexistence of trees in tropical forests: spatial signals of topographic niche differentiation increase with environmental heterogeneity

Neutral and niche theories give contrasting explanations for the maintenance of tropical tree species diversity. Both have some empirical support, but methods to disentangle their effects have not yet been developed. We applied a statistical measure of spatial structure to data from 14 large tropical forest plots to test a prediction of niche theory that is incompatible with neutral theory: that species in heterogeneous environments should separate out in space according to their niche preferences. We chose plots across a range of topographic heterogeneity, and tested whether pairwise spatial associations among species were more variable in more heterogeneous sites. We found strong support for this prediction, based on a strong positive relationship between variance in the spatial structure of species pairs and topographic heterogeneity across sites. We interpret this pattern as evidence of pervasive niche differentiation, which increases in importance with increasing environmental heterogeneity.

Chemical mutagenesis testing in Drosophila: I. Comparison of positive and negative control data for sex-linked recessive lethal mutations and reciprocal translocations in three laboratories

As part of the validation phase of the Drosophila melanogaster segment of the National Toxicology Program, a comparison has been made of positive and negative controls for sex-linked recessive lethal mutations and reciprocal translocations from three laboratories. This comparison involves approximately 700,000 spontaneous recessive lethal mutation tests, 70,000 spontaneous translocation tests, and screens for genetic damage induced by N-nitrosodimethylamine and beta-propiolactone. Spontaneous frequencies for lethal mutations and translocations were homogeneous in the laboratories regardless of solvent or broods sampled. Inhomogeneity was observed in induced frequencies among laboratories, but the variation was no greater than that found within a laboratory.

[Alignment of the sagittal profile after surgical therapy of nonspecific destructive spondylodiscitis: ventral or ventrodorsal method--a comparison of outcomes]

From 1989 to 1998, 129 patients underwent surgery for unspecific spondylodiscitis in the Department of Orthopedics of the Free University of Berlin. Fifty-six of them were followed up, and their clinical and radiological results were evaluated in this study. The surgical results of 40 patients with only ventral removal of a focus and defect coverage with an iliac crest graft were compared to those of 16 with additional dorsal bridging instrumentation by internal fixation. A mean of 2.3 vertebrae were fused in ventral spondylodesis; the mean length of dorsal instrumentation by internal fixation was 3.8 vertebrae. Patients were followed up a mean of 5.1 years after surgery. The mean age of patients was 57.1 years at the time of surgery. Patients were postoperatively mobilized a mean of 5 days after ventrodorsal fusion. A purely ventral procedure required a mean postoperative immobilization period of 3.6 weeks and brace fitting of a mean 8.2 months. There was one case of recurrent spondylodiscitis 25 months postoperatively, which made a revision of the focus necessary. The consolidation rate of the ventral spondylodesis was 84-100% in the different subgroups. A differential view of the spinal areas and ventral fusion segments was used to make a statement about the development of the sagittal spine profile. The segmental position of the spine in the sagittal plane was assessed by comparing the segmental kyphosis angles to normal values in the literature. All subgroups submitted to combined ventrodorsal fusion had a greater preoperative segmental kyphosis angle than those undergoing ventral fusion alone. In marked segmental kyphotic false positioning, the combined ventrodorsal procedure achieved good postoperative repositioning results, and an increase in segmental kyphosis was prevented. Ventral removal of a focus and bone graft spondylodesis seem to be adequate in single-level spondylodiskitis especially in the lumbar spine, but additional dorsal instrumentation should be performed in the case of long ventral fusion.

Chemical mutagenesis testing in Drosophila. IX. Results of 50 coded compounds tested for the National Toxicology Program

Fifty chemicals were tested for mutagenic activity in post-meiotic and meiotic germ cells of male Drosophila melanogaster using the sex-linked recessive lethal (SLRL) assay. As in the previous studies in this series, feeding was chosen as the first route of administration. If the compound failed to induce mutations by this route, injection exposure was used. One gaseous chemical (1,3-butadiene) was tested only by inhalation. Those chemicals that were mutagenic in the sex-linked recessive lethal assay were further tested for the ability to induce reciprocal translocations. Eleven of the 50 chemicals tested were mutagenic in the SLRL assay. These included bis(2-chloroethyl) ether, 1,4-butanediol diglycidyl ether, 1-chloro-2-propanol, dimethyl methylphosphonate, dimethyl morpholinophosphoramidate, dimethyloldihydroxyethylene urea, 2,2-dimethyl vinyl chloride, hexamethylphosphoramide, isatin-5-sulfonic acid (Na salt), isopropyl glycidyl ether, and urethane. Five of these, including 1,4-butanediol diglycidyl ether, 2,2-dimethyl vinyl chloride, hexamethylphosphoramide, isopropyl glycidyl ether, and urethane, also induced reciprocal translocations.

Genotoxicity studies of methyl isocyanate in Salmonella, Drosophila, and cultured Chinese hamster ovary cells

The genotoxic effects of methyl isocyanate (MIC) were investigated using four short-term tests: the Salmonella reversion assay (Ames test), the Drosophila sex-linked recessive lethal assay, and the sister chromatid exchange (SCE) and chromosomal aberration assays in cultured Chinese hamster ovary (CHO) cells. No evidence was found for the induction of mutations in either Salmonella or Drosophila. MIC did, however, induce SCEs and chromosomal aberrations in CHO cells both in the presence and absence of Aroclor-induced rat liver S-9.

Phosphate immobilization using an acidic type F fly ash

Batch equilibration experiments using a low calcium ( approximately 1 wt.% as CaO), acidic (pH approximately 4.5) Type F fly ash demonstrated phosphate immobilization on the order of 100% to 75% for 50 and 100 mg P/l solutions, respectively. A loosely compacted column of fly ash similarly removed 10 mg P/l for over 85 pore volumes. While the interactions between phosphate and calcium-rich (Type C) ashes are relatively well understood, insight into the mechanisms of phosphate immobilization in Type F ash necessitated a review of the phosphate chemistry and interactions with acidic geomedia. Phosphate adsorption was subsequently modeled using a constant capacitance model approach (CCM) excluding precipitation reactions. Our CCM predictions of total phosphate immobilization (20%) were substantially less than the results of the batch equilibration experiments and phosphate adsorption predicted by other researchers examining near pure natural and synthetic geomedia due to the compositional heterogeneity of the fly ash. Nevertheless, for the amorphous and crystalline phases studied, the immobilization of phosphate in the Type F fly ash is attributed to the formation of insoluble aluminum and iron phosphates at low to medium values of pH.

The effect of hydraulic conditions on waste stabilisation in bioreactor landfill simulators

Seven bioreactor landfill simulators (mixed gravel, gravel in layers, and controls without gravel with two levels of compaction, i.e. normal and lower density) were used to investigate the effect of different hydraulic conditions on the waste stabilisation process. The simulators with mixed gravel showed a higher degree of waste stabilisation towards the end of the experiment due to higher moisture content, whereas the other simulators were prone to clogging thus reducing the overall treatment effectiveness. Moreover, reaching neutral pH levels seemed to be the "driving force" that enhanced physical, chemical and biological processes contributing to waste stabilisation in the simulators with mixed gravel. After one year of operation, the residues of the different simulators were very close to achieve a final storage quality status comparable to the waste acceptance criteria for inert waste of the European landfill directive.

The genetic toxicology of Kathon biocide, a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one

Kathon biocide, an aqueous solution containing a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one in an approximate ratio of 3:1, was tested for mutagenic activity in Salmonella typhimurium, L5178Y mouse lymphoma cells in culture and Drosophila melanogaster. Tests also were conducted for chromosome aberrations in vivo on mouse bone marrow cells, for DNA damage/repair in primary rat hepatocytes in culture, and for morphological transformation in C3H 10T1/2 cells in culture. Kathon biocide produced point mutations in the absence of a rat-liver metabolizing system in bacteria (strain TA 100) and mammalian cells in culture. In the presence of rat-liver metabolizing system a 10-fold higher concentration was required to induce point mutations in mammalian cells in culture. No mutagenic activity was observed with the metabolizing system and S. typhimurium. Negative results were obtained in the sex-linked recessive lethal assay in Drosophila, the in vivo cytogenetic assay in mice, the unscheduled DNA synthesis assay in cultured rat hepatocytes, and the in vitro cell transformation assay.

Modifications of hepatic alpha-1-acid glycoprotein and albumin gene expression in rats treated with phenobarbital

The serum level of alpha 1-acid glycoprotein (alpha 1-AGP) is significantly increased in various animal species by treatment with cytokines, glucocorticoids and phenobarbital. The mechanisms responsible for the cytokine-induced and glucocorticoid-induced increases are now well documented, but not so in the case of phenobarbital. The main purpose of this study was to assess whether phenobarbital acts on alpha 1-AGP synthesis in the liver at the transcriptional or translational level. Male Dark Agouti rats received 70 mg phenobarbital/kg daily for 7 days. The analysis of total hepatic RNA showed that a single injection of phenobarbital induced an 11-fold increase in phenobarbital-dependent cytochrome P450IIB mRNA, whereas seven injections of phenobarbital were required to induce a maximum 5.5-fold increase in alpha 1-AGP mRNA. Concurrently, the transcription rate of the alpha 1-AGP gene rose 3.5-fold. Hepatocytes isolated after the seventh injection of phenobarbital showed a threefold increased capacity to secrete alpha 1-AGP, corresponding to a 3.2-fold increased alpha 1-AGP mRNA content in the liver. In conditions in which its effect on the induction of alpha 1-AGP synthesis was maximum, phenobarbital caused a 30% reduction in liver albumin mRNA and in albumin secretion by isolated hepatocytes, resulting from a 60-70% reduction in the rate of transcription of the albumin gene measured in isolated nuclei. We conclude that the effect of phenobarbital on alpha 1-AGP and albumin gene expression occurs at the transcriptional rather than the translational level.

Evolution of ornithine decarboxylase activity during the cell cycle of Euglena gracilis Z in synchronous culture. Influence of vitamin B-12

Ornithine decarboxylase activity in Euglena gracilis Z was studied during the normal cell cycle and in vitamin B-12 deficiency. The cells were synchronized by means of alternating periods of light and dark. During the normal cell cycle, ornithine decarboxylase activity was very weak in the dark period, while three peaks of activity were recognized in the light period. The first peak, in the G1 phase, occurred when luminous stimulation started; the second preceded the S phase and the third was found in G2. In B-12-deficient cells, ornithine decarboxylase activity was greatly decreased and only the first peak remained. Elimination of the deficiency by addition of vitamin B-12 to the medium induced a very fast and significant increase in ornithine decarboxylase activity.