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Understanding intramammary estrogen homeostasis constitutes the basis of understanding the role of lifestyle factors in breast cancer etiology. Thus, the aim of the present study was to identify variables influencing levels of the estrogens present in normal breast glandular and adipose tissues (GLT and ADT, i.e., 17β-estradiol, estrone, estrone-3-sulfate, and 2-methoxy-estrone) by multiple linear regression models. Explanatory variables (exVARs) considered were (a) levels of metabolic precursors as well as levels of transcripts encoding proteins involved in estrogen (biotrans)formation, (b) data on breast cancer risk factors (i.e., body mass index, BMI, intake of estrogen-active drugs, and smoking) collected by questionnaire, and (c) tissue characteristics (i.e., mass percentage of oil, oil%, and lobule type of the GLT). Levels of estrogens in GLT and ADT were influenced by both extramammary production (menopausal status, intake of estrogen-active drugs, and BMI) thus showing that variables known to affect levels of circulating estrogens influence estrogen levels in breast tissues as well for the first time. Moreover, intratissue (biotrans)formation (by aromatase, hydroxysteroid-17beta-dehydrogenase 2, and beta-glucuronidase) influenced intratissue estrogen levels, as well. Distinct differences were observed between the exVARs exhibiting significant influence on (a) levels of specific estrogens and (b) the same dependent variables in GLT and ADT. Since oil% and lobule type of GLT influenced levels of some estrogens, these variables may be included in tissue characterization to prevent sample bias. In conclusion, evidence for the intracrine activity of the human breast supports biotransformation-based strategies for breast cancer prevention. The susceptibility of estrogen homeostasis to systemic and tissue-specific modulation renders both beneficial and adverse effects of further variables associated with lifestyle and the environment possible. Electronic supplementary material The online version of this article (10.1007/s00204-020-02807-1) contains supplementary material, which is available to authorized users.

Reservoir quality (RQ) prediction models for sandstones in use by the oil and gas industry primarily emulate mechanical compaction, quartz cementation, and cementation by a few select aluminosilicate minerals during burial. The modeled cements are treated on a kinetic basis using independent Arrhenius-style rate equations, and nonmodeled cements are constrained by empirical observations and data from analog rocks. The nonmodeled cements pose a significant modeling challenge in complex lithic and arkosic sandstones that contain carbonate, clay, or zeolite cements when analog data are not available for constraint. Twenty-nine samples covering a broad range of sandstone compositions were selected from four fields in four different sedimentary basins to investigate the potential of using modern reactive transport models (RTM) to simulate a more comprehensive suite of minerals involved in sandstone diagenesis. A commercially available RTM, GWB® X1t, was configured to model chemical diagenesis in a time–temperature burial framework conceptually similar to that employed in standard industry RQ forward models. Strategies were developed to consistently constrain kinetic parameters, fluid compositions, and fluid fluxes with the goal of standardizing these parameters to reduce configuration and calibration time. Results show that RTM using such standardized parameters can reproduce relative timing and volume changes caused by mineral dissolution and precipitation that are accurate within the uncertainty of the petrographic data constraint. The results suggest that incorporation of RTM into current industry models could provide a valuable improvement to siliciclastic RQ prediction in frontier plays with complex mineralogies wherever calibration data are sparse or unavailable.

Because of its assumed role in breast cancer etiology, estrogen biotransformation (and interaction of compounds therewith) has been investigated in human biospecimens for decades. However, little attention has been paid to the well-known fact that large inter-individual variations exist in the proportion of breast glandular (GLT) and adipose (ADT) tissues and less to adequate tissue characterization. To assess the relevance of this, the present study compares estrogen biotransformation in GLT and ADT. GLT and ADT were isolated from 47 reduction mammoplasty specimens derived from women without breast cancer and were characterized histologically and by their percentages of oil. Levels of 12 unconjugated and five conjugated estrogens were analyzed by GC- and UHPLC-MS/MS, respectively, and levels of 27 transcripts encoding proteins involved in estrogen biotransformation by Taqman® probe-based PCR. Unexpectedly, one-third of specimens provided neat GLT only after cryosection. Whereas 17β-estradiol, estrone, and estrone-3-sulfate were detected in both tissues, estrone-3-glucuronide and 2-methoxy-estrone were detected predominately in GLT and ADT, respectively. Estrogen levels as well as ratios 17β-estradiol/estrone and estrone-3-sulfate/estrone differed significantly between GLT and ADT, yet less than between individuals. Furthermore, estrogen levels in GLT and ADT correlated significantly with each other. In contrast, levels of most transcripts encoding enzymes involved in biotransformation differed more than between individuals and did not correlate between ADT and GLT. Thus, mixed breast tissues (and plasma) will not provide meaningful information on local estrogen biotransformation (and interaction of compounds therewith) whereas relative changes in 17β-estradiol levels may be investigated in the more abundant ADT.

Geochemical interactions between shale and hydraulic fracturing fluid may affect produced-water chemistry and rock properties. It is important to investigate the rock–water reactions to understand the impacts. Eight autoclave experiments reacting Marcellus and Eagle Ford Shale samples with synthetic brines and a friction reducer were conducted for more than 21 days. To better determine mineral dissolution and precipitation at the rock–water interface, the shale samples were ion milled to create extremely smooth surfaces that were characterized before and after the autoclave experiments using scanning electron microscopy (SEM). This method provides an unprecedented level of detail and the ability to directly compare the same mineral particles before and after the reaction experiments. Dissolution area was quantified by tracing and measuring the geometry of newly formed pores. Changes in porosity and permeability were also measured by mercury intrusion capillary pressure (MICP) tests. Aqueous chemistry and SEM observations show that dissolution of calcite, dolomite, and feldspar and pyrite oxidation are the primary mineral reactions that control the concentrations of Ca, Mg, Sr, Mn, K, Si, and SO4 in aqueous solutions. Porosity measured by MICP also increased up to 95%, which would exert significant influence on fluid flow in the matrix along the fractures. Mineral dissolution was enhanced and precipitation was reduced in solutions with higher salinity. The addition of polyacrylamide (a friction reducer) to the reaction solutions had small and mixed effects on mineral reactions, probably by plugging small pores and restricting mineral precipitation. The results suggest that rock–water interactions during hydraulic fracturing likely improve porosity and permeability in the matrix along the fractures by mineral dissolution. The extent of the geochemical reactions is controlled by the salinity of the fluids, with higher salinity enhancing mineral dissolution.

Despite being widely used to investigate 17β-estradiol (E2)-induced mammary gland (MG) carcinogenesis and prevention thereof, estrogen homeostasis and its significance in the female August Copenhagen Irish (ACI) rat model is unknown. Thus, levels of 12 estrogens including metabolites and conjugates were determined mass spectrometrically in 38 plasmas and 52 tissues exhibiting phenotypes ranging from normal to palpable tumor derived from a representative ACI study using two different diets. In tissues, 40 transcripts encoding proteins involved in estrogen (biotrans)formation, ESR1-mediated signaling, proliferation and oxidative stress were analyzed (TaqMan PCR). Influence of histo(patho)logic phenotypes and diet on estrogen and transcript levels was analyzed by 2-way ANOVA and explanatory variables influencing levels and bioactivity of estrogens in tissues were identified by multiple linear regression models. Estrogen profiles in tissue and plasma and the influence of Hsd17b1 levels on intra-tissue levels of E2 and E1 conclusively indicated intra-mammary formation of E2 in ACI tumors by HSD17B1-mediated conversion of E1. Proliferation in ACI tumors was influenced by Egfr, Igf1r, Hgf and Met levels. 2-MeO-E1, the only oxidative estrogen metabolite detected above 28–42 fmol/g, was predominately observed in hyperplastic tissues and intra-tissue conversion of E1 seemed to contribute to its levels. The association of the occurrence of 2-MeO-E1 with higher levels of oxidative stress observed in hyperplastic and tumor tissues remained equivocal. Thus, the present study provides mechanistic explanation for previous and future results observed in the ACI model.

Human African trypanosomiasis (HAT) is a major tropical disease for which few drugs for treatment are available, driving the need for novel active compounds. Recently, morpholino-substituted benzyl amides of the fluoroquinolone-type antibiotics were identified to be compounds highly active against Trypanosoma brucei brucei . Since the lead compound GHQ168 was challenged by poor water solubility in previous trials, the aim of this study was to introduce structural variations to GHQ168 as well as to formulate GHQ168 with the ultimate goal to increase its aqueous solubility while maintaining its in vitro antitrypanosomal activity. The pharmacokinetic parameters of spray-dried GHQ168 and the newly synthesized compounds GHQ242 and GHQ243 in mice were characterized by elimination half-lives ranging from 1.5 to 3.5 h after intraperitoneal administration (4 mice/compound), moderate to strong human serum albumin binding for GHQ168 (80%) and GHQ243 (45%), and very high human serum albumin binding (>99%) for GHQ242. For the lead compound, GHQ168, the apparent clearance was 112 ml/h and the apparent volume of distribution was 14 liters/kg of body weight (BW). Mice infected with T. b. rhodesiense (STIB900) were treated in a stringent study scheme (2 daily applications between days 3 and 6 postinfection). Exposure to spray-dried GHQ168 in contrast to the control treatment resulted in mean survival durations of 17 versus 9 days, respectively, a difference that was statistically significant. Results that were statistically insignificantly different were obtained between the control and the GHQ242 and GHQ243 treatments. Therefore, GHQ168 was further profiled in an early-treatment scheme (2 daily applications at days 1 to 4 postinfection), and the results were compared with those obtained with a control treatment. The result was statistically significant mean survival times exceeding 32 days (end of the observation period) versus 7 days for the GHQ168 and control treatments, respectively. Spray-dried GHQ168 demonstrated exciting antitrypanosomal efficacy.

The α,β-unsaturated carbonyl group is recognized as alert for mutagenicity, attributed to (1) its direct reaction with DNA, counteractable by glutathione (GSH), and (2) oxidative stress caused indirectly by GSH depletion. Accordingly, the α,β,γ,δ-unsaturated lactone patulin (PAT), a mycotoxin detected in fruits and products derived thereof, is known to induce gene, chromosome, and genome mutations in vitro, its mutagenicity correlating inversely with intracellular GSH levels. Thus, the reactivity of PAT against DNA bases and nucleosides in the absence and presence of GSH and glutathione S-transferases (GSTs) was investigated under cell-free conditions using HPLC mass spectrometry techniques for identification of reaction products. Adduct formation with all four nucleobases as well as with purine base nucleosides occurred even in the presence of GSH, revealing several adducts of PAT, mono- and disubstituted with nucleobases/nucleosides as well as novel GSH-PAT adducts. In addition, novel mixed GSH-PAT-nucleobase adducts were observed. These adducts exhibited a ketohexanoic acid-type structure of the PAT molecule, C6 substituted with GSH and linking C1 of PAT with nitrogens of nucleobases/nucleosides via an amide bond. Formation of GSH-PAT-adenine adducts was not prevented by GSTs, and excess of GSH needed to reduce their formation was higher than for PAT-adenine adducts. The formation of mixed GSH-DNA base adducts has not been described for PAT or any other α,β-unsaturated carbonyl before, although the reaction mechanism seems to be applicable to a variety of α,β-unsaturated carbonyls occurring in food and in the environment.

We present a new class of hybrid molecules consisting of the established antiplasmodial drugs primaquine and chloroquine. No drug is known to date that acts comparably against all stages of Plasmodium in its life cycle. Starting from available precursors, we designed and synthesized a new-generation compound consisting of both primaquine and chloroquine components, with the intent to produce agents that exhibit bioactivity against different stages of the parasite's life cycle. In vitro, the hybrid molecule 3 displays activity against both asexual and sexual P. falciparum blood stages as well as P. berghei sporozoites and liver stages. In vivo, the hybrid elicits activity against P. berghei liver and blood stages. Our results successfully validate the concept of utilizing one compound to combine different modes of action that attack different Plasmodium stages in the mammalian host. It is our hope that the novel design of such compounds will outwit the pathogen in the spread of drug resistance. Based on the optimized synthetic pathway, the compound is accessible in a smooth and versatile way and open for potential further molecular modification.

A recent intervention study demonstrated the occurrence of irilone as second most abundant isoflavone next to daidzein in human plasma after consumption of a red clover-based dietary supplement (RCDS) containing predominately formononetin ≫ biochanin A > irilone (12 % of these isoflavones). To elucidate the relevance of this finding, in the present study (1) the representativeness of the isoflavone composition of the RCDS and (2) the estrogenic activity of irilone were investigated. Thus, major isoflavones were quantified in eight commercially available RCDS. Furthermore, the estrogenic activities of irilone and other isoflavones were determined by marker gene expression in Ishikawa and cell proliferation in MCF-7 cells. Irilone amounted to 1.8–10.9 mg/g capsule content and 5–18 % of the three major isoflavones, respectively, demonstrating the general occurrence of irilone in RCDS. Moreover, irilone significantly induced the activity of alkaline phosphatase (AlP) as well as AlP, progesterone receptor, and androgen receptor mRNA levels in Ishikawa cells. Furthermore, irilone significantly induced MCF-7 cell proliferation. Neither 17β-estradiol (E2)-induced AlP activity nor E2-induced MCF-7 cell proliferation was affected by irilone. ICI182,780 antagonized IRI-induced effects on both AlP activity and cell proliferation, suggesting an estrogen receptor agonistic mode of action. Taking into account the estrogenic activity of red clover isoflavones (formononetin, biochanin A, prunetin, glycitein) and their biotransformation products (daidzein, genistein, ethylphenol) as well as published plasma levels of isoflavones after consumption of RCDS, irilone could contribute approximately 50 % of the E2 equivalents estimated for daidzein.

In Eastern Asia, coronary heart disease as well as breast and prostate cancer are less frequent than in Western countries, which is considered to be due to the Asian diet. Because Asians consume much more soy-based food products, putative beneficial health effects of soy and soy isoflavones have attracted much attention in the past two decades. Yet, although a plethora of cell-free studies, studies in vitro and in vivo, and studies in humans have investigated a multitude of putatively beneficial biological effects, no health claim directly related to isoflavones has been approved up to now. Likewise, despite ongoing safety evaluation of isoflavones by scientific expert panels, no conclusion is expected to be released in the near future. The present chapter summarizes the current knowledge on toxicity and efficacy of isoflavones, focusing on biokinetic properties of isoflavones necessary to understand the heterogeneity of study results and other difficulties in evaluating safety and efficacy of isoflavones.

We have developed process-based models for early grain coats and their impact on deep reservoir quality in the Jurassic eolian Norphlet Formation, Alabama, with implications for exploration and development in other conventional and tight-gas continental reservoirs. The Norphlet, a major gas reservoir to depths of 21,800 ft (6645 m) and temperatures of 419F (215C), displays contrasting intervals of high and low reservoir quality within compositionally similar cross-bedded eolian sands. Study results show that grain coats formed soon after deposition are responsible for differences in deep Norphlet porosity of up to 20% and permeability up to 200 md. Three types of grain coats were identified in Norphlet dune sands, each formed in a different part of a shallow groundwater system, and each with distinctive impact on deep reservoir quality. Diagenetic chlorite coats, formed where dunes subsided into shallow hypersaline groundwater, preserve good deep porosity (to 20%) and permeability (to 200 md). Continuous tangential illitic coats, formed in the vadose zone of stabilized dunes exposed to periodic fresh-water influx, preserve good deep porosity (to 15%) associated with poor permeability (1 md) due to linked formation of later high-temperature diagenetic illite. Discontinuous grain coats, formed in active dunes where grains were abraded by eolian transport, are associated at depth with tight zones of pervasive quartz cement, low porosity (8%), and low permeability (1 md). These concepts plus data from 60 wells were used to derive bay-wide predictive tight and porous-zone isopachs that can be used for well placement, geologic models, and field development.

The isoflavone irilone is found in human plasma after ingestion of red clover-based dietary supplements, but information allowing safety assessment is rare. Here, data in support of the mutagenic potential of irilone in cultured V79 cells [1] are presented. These data include (i) a quantitative assessment of irilone in the culture medium during the cell culture experiments, (ii) changes in the mutation spectrum in cDNA of the hypoxanthine-guanine phosphoribosyltransferase locus of irilone-treated V79 cells, (iii) occurrence of karyorrhexis and apoptosis as well as (iv) number of micronucleated cells containing whole chromosomes or chromosomal fragments. Also exemplary micrographs, used for the fluorescence microscopic assessment of (iii) and (iv) are presented.

The Grb2-associated binder-1 (Gab1) is one of the major adapter molecules downstream of growth factor receptor signaling. Even though insulin causes tyrosine phosphorylation of Gab1, its role in insulin signaling has not been identified yet. We have demonstrated that insulin increased expression of early growth response gene-1 (egr-1), which is one of the most important transcription factors involved in cell proliferation and differentiation. In the present study, the possible role of Gab1 in insulin-induced egr-1 expression was studied using Rat1 fibroblasts expressing human insulin receptors and wildtype Gab1 (HIRc/Gab1(WT)), Gab1 with three tyrosines in the phosphatidylinositol (PI) 3'-kinase binding domain mutated to phenylalanine (HIRc/Gab1(DeltaPI3K)), or histidinol resistance only (HIRc/HIS). Insulin-induced egr-1 expression in HIRc/Gab1(DeltaPI3K) cells was much lower than in the other cells, as determined by Northern blot analysis. These results suggest that Gab1 is involved in the signaling pathway for insulin-induced egr-1 expression through increasing PI3'-kinase activity. The MAP kinase activity increased less with insulin treatment in HIRc/Gab1(DeltaPI3K) cells than in other cells. Inhibition of MAP kinase by the MEK inhibitor completely abolished insulin-induced egr-1 expression. These results suggest that Gab1 increases MAP kinase activity through its PI3'-kinase binding site, which then leads to egr-1 expression. Our results indicate that Gab1 is involved in the control of egr-1 expression regulated by insulin.

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants with myriad biological effects, including carcinogenicity. We present data showing gender-specific genotoxicity in Fischer 344 transgenic BigBlue rodents exposed to 4-chlorobiphenyl (PCB3), a hydroxylated metabolite, and the positive control 3-methylcholanthrene (3-MC) where female rats are more resistant to the genotoxic effects of the test compounds compared to their male counterparts. This difference is further highlighted through our examination of gene expression, organ-specific weight changes, and tissue morphology. The purpose of the present study was to explore the complex and multifaceted issues of lower molecular weight PCBs as initiators of carcinogenesis, by examining the mutagenicity of PCB3, a hydroxylated metabolite (4′-OH-PCB3), and 3-methylcholanthrene (3-MC, positive control) in a transgenic rodent model. Previous findings indicated that PCB3 is mutagenic in the liver of male BigBlue transgenic rats under identical exposure conditions. We expected that female rats would be equally, if not more sensitive than male rats, since a 2-year carcinogenesis bioassay with Sprague–Dawley rats and commercial PCB mixtures reported much higher liver cancer rates in female than in male rats. The current study, however, revealed a similar trend in the mutation frequencies across all four treatment groups in females as reported previously in males, but increased variability among animals within each group and a lower overall effect, led to non significant differences in mutation frequencies. A closer analysis of the possible reasons for this negative result using microarray, organ weight and histology data comparisons shows that female Fischer 344 rats 1) had a higher baseline mutation frequency in the corn oil control group and greater variability than male rats; 2) responded with robust gene expression changes, which may also play a role in our observation of 3) highly increased liver, spleen, and lung weight in 3-MC and PCB3-treated female rats and thus changed distribution and kinetics of the test compounds. Our analysis indicates that female transgenic BigBlue Fischer 344 rats are more resistant to PCB3 and 3-MC genotoxicity compared to their male counterparts. Keywords: Polychlorinated biphenyl, PCB3, 3-methylcholanthrene, 3-MC, Gender difference, Genotoxicity, Biotransformation, Carcinogenicity

Many currently producing shale-gas reservoirs are overmature oil-prone source rocks. Through burial and heating these reservoirs evolve from organic-matter-rich mud deposited in marine, lacustrine, or swamp environments. Key characterization parameters are: total organic carbon (TOC), maturity level (vitrinite reflectance), mineralogy, thickness, and organic matter type. Hydrogen-to-carbon (HI) and oxygen-to-carbon (OI) ratios are used to classify organic matter that ranges from oil-prone algal and herbaceous to gas-prone woody/coaly material.Although organic-matter-rich intervals can be hundreds of meters thick, vertical variability in TOC is high (Typical analysis techniques for shale-gas reservoir rocks include: TOC, X-ray diffraction, adsorbed/canister gas, vitrinite reflectance, detailed core and thin-section descriptions, porosity, permeability, fluid saturation, and optical and electron microscopy. These sample-based results are combined with full well-log suites, including high resolution density and resistivity logs and borehole images, to fully characterize these formations. Porosity, fluid saturation, and permeability derived from core can be tied to log response; however, several studies have shown that the results obtained from different core analysis laboratories can vary significantly, reflecting differences in analytical technique, differences in definitions of fundamental rock and fluid properties, or the millimeter-scale variability common in mudstones that make it problematic to select multiple samples with identical attributes.Porosity determination in shale-gas mudstones is complicated by very small pore sizes and, thus, large surface area (and associated surface water); moreover, smectitic clays that are commonly present in mud have interlayer water, but this clay family tends to be minimized in high maturity formations due to illitization. Finally, SEM images of ion-beam-milled samples reveal a separate nano-porosity system contained within the organic matter, possibly comprising >50% of the total porosity, and these pores may be hydrocarbon wet, at least during most of the thermal maturation process. A full understanding of the relation of porosity and gas content will result in development of optimized processes for hydrocarbon recovery in shale-gas reservoirs.

The local lymph node assay (LLNA) is the assay of choice in European regulatory toxicology. As with other toxicology/sensitisation assays, it has a potential for false results, the anionic surfactant sodium lauryl sulphate (SLS) representing a classic example. In the work reported here, examples of false positives in the LLNA are compared to published "benchmarks" such as SLS. Clear false positives (e.g. oleic acid) are also contrasted with examples where data interpretation is more challenging. As the LLNA will be applicable to >30,000 chemicals under REACH, and in the light of animal welfare considerations to do no more than the absolute minimum of animal testing, results from a single LLNA often represent the only available data on sensitisation. This reinforces the need to ensure data from this assay are interpreted intelligently, using scientific analysis of results and considering the weight of evidence, before decisions are made on which substances should be classified as representing a skin sensitisation hazard. In chemical classes where the LLNA has been shown to be an inappropriate assay other standardised methods (e.g. the Buehler or Magnusson and Kligman guinea pig tests [OECD 406]) should be employed as the first choice assays.

Many higher-chlorinated biphenyls, persistent and predominant in foods, are active as promoters in hepatocarcinogenesis. Lower-chlorinated biphenyls, predominating in indoor and outdoor air, are more readily metabolized and therefore shorter lived, 'episodic' contaminants. Thus inhalation of such lower chlorinated biphenyls may expose humans to reactive, possibly genotoxic/carcinogenic intermediates. Lower chlorinated biphenyls may be metabolized via arene-oxides to mono- and dihydroxylated intermediates and further to (semi)quinones, highly reactive intermediates. Covalently bound lower chlorinated biphenyls have been detected in rodent tissues in vivo. We recently showed using the modified Solt-Farber foci assay that several mono- to tetrachlorinated biphenyls have initiating activity in the livers of rats. In a follow-up study of PCB3 (4-chlorobiphenyl) metabolites only one monohydroxy- and one quinoid- metabolite showed initiating activity, indicating that the metabolic activation of PCB3 proceeds via hydroxylation and oxidation to the 3,4-quinone, the ultimate carcinogen. Since cancer initiation is based on genotoxic event(s), we hypothesized that PCB3 and/or its metabolite(s) are mutagenic in rat liver in vivo. To investigate this, BigBlue® rats, transgenic for the lacI reporter gene, were exposed to PCB3 and 4-hydroxy-PCB3 (4-HO-PCB3). In male rats the mutant frequency (MF) of lac I in the liver was significantly elevated and the mutation spectrum differed significantly from the control. 4-HO-PCB3 caused a non-significant (p = 0.115) doubling of the MF compared to the control. These studies prove that lower halogenated biphenyls may be metabolically activated in vivo to genotoxic and initiating intermediates.

4-monochlorobiphenyl (PCB3) is found in small amounts in commercial PCB mixtures, indoor and outdoor air, and in food. In contrast to highly chlorinated congeners that are more resistant to metabolic attack, PCB3 is more readily converted by xenobiotic-metabolizing enzymes to monohydroxy-PCBs and further to dihydroxy-metabolites, which can be oxidized to quinones. Our recent studies demonstrated the initiating action of PCB3 in the livers of male rats. Therefore we hypothesized that PCB3 and/or its metabolite(s) are mutagenic in rat livers in vivo. To investigate the mutagenicity and the types of mutations generated by PCB3, male Fischer 344 BigBlue rats, transgenic for the lacI gene, were injected intraperitoneally with PCB3 (600 micromol/kg), 4-hydroxy-PCB3 (4-HO-PCB3, 400 micromol/kg), 3-methylcholanthrene (3-MC, 300 micromol/kg, positive control) and corn oil (negative control) once per week, for 4 weeks. Animals were killed 17 days after the last injection and the mutant frequency of the liver lacI gene determined. 3-MC induced a 4-fold increase of the mutant frequency of the lacI gene in the liver. The mutant frequency in PCB3-treated animals was also significantly elevated. In contrast, 4-HO-PCB3 induced a non-significant doubling of the mutant frequency. The mutation spectrum of solvent control mutants was characterized by transitions, whereas in 3-MC-animals, transversion and frameshift mutations predominated. The PCB3-induced mutation spectrum was similar to that of the 3-MC-induced mutants. In contrast, the mutation spectrum of the 4-HO-PCB3 group hardly differed from that of the control animals. This study demonstrates for the first time the mutagenicity of a PCB in vivo.

The soy isoflavone daidzein (DAI) is known to undergo metabolism to equol (EQO) and to 3′-hydroxy-DAI (3′-HO-DAI) and 6-hydroxy-DAI (6-HO-DAI) in humans. In order to better understand the implications of soy diets for human health, the hormonal and genotoxic activities of these DAI metabolites were studied in cultured human endometrial carcinoma cells. When the estrogenicity was tested by cell-free binding to recombinant human estrogen receptor (ER) α and β as well as by the induction of enzyme activity and gene expression of alkaline phosphatase (ALP) in Ishikawa cells, the ranking order was EQO > DAI > 3′-HO-DAI > 6-HO-DAI. All compounds had a higher affinity to ERβ than to ERα. No significant anti-estrogenic effects of the DAI metabolites were observed in the cells at non-cytotoxic concentrations. The in vitro genotoxicity was assessed by analyzing effects on cell cycle distribution and cell morphology as well as the induction of micronuclei (MN). EQO caused a slight increase in G1 and decrease in S phase of the cell cycle, and slightly but significantly induced kinetochore-positive as well as kinetochore-negative MN and an elevated proportion of abnormal mitotic spindles. 3′-HO-DAI, but not 6-HO-DAI, induced kinetochore-negative MN. The observation that major human metabolites of DAI exhibit estrogenic and genotoxic potential may be of relevance for the safety evaluation of diets containing soy isoflavones.

Extended Horizontal Branch (EHB) stars are observed in many globular clusters and as field stars in the Galactic halo. They belong to old stellar populations of the halo and the old disk. Their evolutionary status is unclear, and still a current subject of debate. Current interest in these stars arise from their association with the discoveries of helium abundance inhomogeneities in the globular clusters ω Cen and NGC 2808. The origin of the inhomogeneities is not yet understood, but there are many interpretations. In order to better understand EHB stars, we explore the evolution of standard blue Horizontal Branch (HB) models using up-to-date physics. We present several grids of post Zero Age Horizontal Branch (post-ZAHB) evolutionary models to include both canonical and non-canonical evolutionary scenarios, as well as to compare models that contain semi-convection to models without semi-convection. We follow the models to the termination of nuclear helium burning. The detailed properties of the models, including shell flashes and breathing pulses, are described.

Alu-Polymerase chain reaction (PCR) was used to amplify human DNA from complex mixed sources of DNA. Amplification of human DNA sequences by Alu-PCR could be accomplished in samples containing low concentrations of template in the presence of excess heterologous DNA sequences. Thus, sensitivity and specificity are maintained in complex DNA mixtures allowing positive identification of the presence of human DNA sequences by this technique.

The recovery of monodisperse inhaled particles from humans in vivo and from excised human and canine lungs was measured after a single breath for particles suspended in air and in mixtures of He or SF6 with O2. Comparisons were made using the unique particle sizes for which the intrinsic particle motions in air and each mixture were identical, so that differences in recovery could be associated with differences in convective flow. For the in vivo tests, only mixtures with 20% O2 were used, while for the excised lungs, mixtures with 10% O2 were also used. In humans in vivo and in excised human lungs, there was significantly greater deposition from He-O2 mixtures and less deposition from SF6-O2 mixtures, with no differences between the in vivo and the excised lung results for the 80-20 mixtures. For the canine lungs, there were no differences in deposition between air and any He or SF6 mixture. The interspecies differences are consistent with the hypothesis that particle exchange between tidal and residual lung gas is dependent on the distance into each airway that is needed to establish a stable flow profile. The more symmetrical branching of human lung airways causes the entry flow into daughter airways to be highly asymmetric, and flow profile rearrangement is greater than that in the monopodal canine lung.

This paper reviews (1) the influence of airflow and particle motion on particle deposition within human lung airways, (2) the effects of carrier gas properties on mass transport in lung airways, and (3) the differences in particle deposition patterns and efficiencies between humans and experimental animals. The primary purpose of this review of general principles and available literature is to identify critical factors affecting the dosimetry of inhaled toxicants. Special attention is paid to studies utilizing gases of varying composition, which illuminate the role of flow profiles and turbulence in gas and particle penetration, and to studies of the effects of interspecies differences in airway branching patterns on particle deposition patterns within the airways.

Whereas dilute solutions of surface active agents modify the properties of cell membranes, particularly in relation to their electrical behaviour, moderate and strong solutions provoke more serious structural damage of the membrane, leading to an increase of its permeability and, finally, to cytolysis. These phenomena have inspired some authors to apply detergents as possible cancer chemotherapeuticals so far, however, with only poor results. The disintegrating effect of tumour emboli into single cells by certain detergents, and the ingenious discovery that the mutual adhesiveness between cancer cells is much less than between normal cells, have led the present authors to investigate the action of some biological surface active agents, alone as well as in some of their associations on the "take" of Yoshida sarcoma implants. Certain associations showed, in contradistinction to the separately applied components, surprisingly favourable activity. It could be established that a correlation actually exists between inhibitory effect and surface activity.