bluuebunny/crossref_metadata_2025 huggingface dataset:
Flavonoids and Other Compounds from the Aerial Parts of Viola etrusca
Authors: Flamini Guido
Published: February 2007

The non‐volatile constituents of the rare species Viola etrusca Erben (Violaceae), collected at Mount Amiata, Italy, were phytochemically investigated for the first time. Two new flavonoid glycosides, 4′‐methoxyrhamnetin (1) and violetruscoside (2), an isorhamnetin derivative, were isolated from the flowering aerial parts, together with eleven known substances, including eight flavonoids, a phenolic acid, glycerin, and a coumarin derivative. The NMR data of violanthin (10) and isoviolanthin (11) are reported for the first time.
Chemosystematic Value of Flavonoids from Crataegus x macrocarpa (Rosaceae) with special Emphasis on (R)‐ and (S)‐Eriodictyol‐7‐O‐glucuronide and Luteolin‐7‐O‐glucuronide
Authors: Ringl Alexandra , Prinz Sonja , Huefner Antje , Kurzmann Michael , Kopp Brigitte
Published: February 2007

The chemotaxonomic investigation of Crataegus x macrocarpa, a hybrid of C. laevigata and C. rhipidophylla, presents the qualitative and quantitative composition of its flavonoid pattern in relationship to its parent species for the first time. Six flavonoids were identified as vitexin‐2″‐O‐rhamnoside (1), vitexin (2), isovitexin (3), rutin (4), hyperoside (5), and isoquercitrin (6). Furthermore, two flavonoids were isolated from C. x macrocarpa and identified as a diastereoisomeric mixture of (R)‐ and (S)‐eriodictyol‐7‐O‐β‐D‐glucuronide (7) and luteolin‐7‐O‐β‐D‐glucuronide (8) by means of 1D‐ and 2D‐NMR, MS, and UV experiments. Compounds 7 and 8 were isolated for the first time from Crataegus species. While missing in C. laevigata, their occurrence in C. rhipidophylla additionally emphasizes its chemotaxonomic relationship to C. x macrocarpa.
Chemical Components from Gentiana aristata
Authors: Wu Quan‐Xiang , Liu Xia , Shi Yan‐Ping
Published: February 2007

Two new, highly oxygenated ursane‐type triterpenoids with an epidioxy function, compounds 1 and 2, as well as a new stanside‐derived iridoid, compound 10, were isolated from the EtOH extract of Gentiana aristata (whole plant), together with 14 known constituents. The structures of the new compounds were established on the basis of detailed spectroscopic investigations, such as 1D‐ and 2D‐NMR spectroscopy, as well as by means of HR‐MS. Compounds 3 and 5–9 were screened in vitro for their cytotoxicities against human promyelocytic leukemia (HL‐60), human ovarian (HO‐8910), and human lung epithelia (A‐549) cancer cells.
Synthesis of Bisubstrate Inhibitors of Porphobilinogen Synthase from Pseudomonas aeruginosa
Authors: Gacond Sabine , Frère Frederic , Nentwich Merle , Faurite Jean‐Philippe , Frankenberg‐Dinkel Nicole , Neier Reinhard
Published: February 2007

Porphobilinogen synthase (PBGS) synthesizes porphobilinogen 2 (PBG), the common precursor of all natural tetrapyrroles, through an asymmetric condensation of two molecules of 5‐aminolevulinic acid 1 (ALA). Symmetrically linked dimers 7–11 derived from levulinic acid 3 (γ‐oxovaleric acid) have been synthesized to mimic the assumed bisubstrate bound to the active site of the enzyme. Their inhibition potential was characterized by determination of the IC50 and Ki values using PBGS from Pseudomonas aeruginosa. The polarity and the size of the functional group linking the two levulinic acid 3 units have a strong influence on the inhibition behavior.
Synthesis and Cytotoxic Evaluation of Novel 7‐O‐Modified Genistein Derivatives
Authors: Zhang Li‐Na , Xiao Zhu‐Ping , Ding Hui , Ge Hui‐Ming , Xu Chen , Zhu Hai‐Liang , Tan Ren‐Xiang
Published: February 2007

Two series of genistein (=5,7‐dihydroxy‐3‐(4‐hydroxyphenyl)‐4H‐1‐benzopyran‐4‐one) derivatives with heterocycles were prepared, in which genistein and heterocyclic moieties were separated by C2 and C3 spacers. Among the 24 compounds we prepared, 22, i.e., 3a–3k and 4a–4k, were reported for the first time, while the preparation of 2a and 2b was reported in our recent paper. The cytotoxic activities of these compounds were evaluated against human chronic myeloid leukemia cells (K562) and a human nasopharyngeal epidermoid tumor cell line (KB). Compounds 4a, 4d, 4e, 4h, and 4i showed remarkable anticancer activities in vitro that are comparable with 5‐fluorouracil, an canonical anticancer drug. Structure–effect relationships were also discussed based on the experimental data obtained.
Predictive value of p53 and pRb expression in superficial bladder cancer patients treated with BCG and interferon‐alpha
Authors: Esuvaranathan Kesavan , Chiong Edmund , Thamboo Thomas Paulraj , Chan Yiong Huak , Kamaraj Revathi , Mahendran Ratha , Teh Ming
Published: February 2007

BACKGROUND

Nuclear p53 and retinoblastoma protein (pRb) were reported to be poor prognostic indicators for transitional cell carcinoma of the bladder. The authors sought to determine the prognostic value of nuclear p53 and pRb in superficial bladder transitional cell carcinoma patients who were treated with intravesical bacille Calmette‐Guerin (BCG) or BCG with interferon‐alpha (IFN‐α).

METHODS

A prospective histological review was performed for 80 superficial bladder transitional cell carcinoma patients who underwent postresection intravesical regimes of BCG (81mg, n = 33 or 27 mg, n = 20) or BCG (27 mg) with IFN‐α (n = 27), and followed for a mean of 4.5 years. Hematoxylin and eosin (H & E) and immunoperoxidase staining were performed on tissue sections. Nuclear p53 and pRb immunoreactivity were assessed semiquantitatively, by using a combination of staining extent and intensity, to categorize overexpression or underexpression. Data were analyzed by using chi‐square analysis, multiple logistic regression, and Kaplan‐Meier curves.

RESULTS

pRb expression was not associated with patient outcome after BCG‐alone therapy, but pRb underexpression was significantly associated with BCG nonresponse and tumor recurrence (P = .047) after BCG and IFN‐α (BCG + IFN‐α) therapy. Low‐grade tumors were associated with pRb overexpression, with or without nuclear p53 underexpression (P = .019; P = .043, respectively). p53 expression alone or in combination with pRb expression had no significant relation with tumor response to BCG alone or BCG + IFN‐α with respect to recurrence, progression, or cancer‐specific death.

CONCLUSIONS

Nuclear pRb underexpression may be predictive of nonresponse and cancer recurrence after intravesical BCG + IFN‐α therapy. Nuclear p53 expression or its combination with pRb expression is not associated with post‐BCG clinical outcome, so p53 expression or p53 with pRb expression should not be used to influence decisions concerning BCG‐alone or BCG + IFN‐α therapy. Cancer 2007. © 2007 American Cancer Society.
Rat retinal microglial cells under normal conditions, after optic nerve section, and after optic nerve section and intravitreal injection of trophic factors or macrophage inhibitory factor
Authors: Sobrado‐Calvo Paloma , Vidal‐Sanz Manuel , Villegas‐Pérez María P.
Published: February 2007

Retinal microglial cells may have a role in both degeneration and neuroprotection of retinal ganglion cells (RGC) after optic nerve (ON) section. We have used NDPase enzymohistochemistry to label adult rat retinal microglial cells and have studied these cells under normal conditions, after left ON section, and after left ON section and eye puncture or intravitreal injection of different substances: vehicle, brain‐derived neurotrophic factor (BDNF), nerve growth factor (NGF), neurotrophin 3 (NT3), or macrophage inhibitory factor (MIF). Resident microglial cells are present in four layers in the adult rat retina: the nerve fiber layer (NFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and outer plexiform layer (OPL). Left ON section induces microglial activation in the ipsilateral and contralateral retina as manifested by stronger staining intensity in both retinas and increased microglial cell densities in the NFL, IPL, and GCL of the ipsilateral retina. Left ON section followed by left eye puncture or intravitreal injection increases microglial cell density in both retinas and induces changes in the microglial cells of the ipsilateral retina that vary depending on the substance injected: BDNF injections delay microglial activation, possibly through retinal ganglion cell neuroprotection, whereas NT3 partially inhibits microglial activation in the NFL; MIF injections have no clear effects on microglial activation. In conclusion, retinal microglial cells become activated after an ON section and react more intensely when the eye is also punctured or injected, and this response may be altered by using neurotrophic factors, although the effects of MIF are less clear. J. Comp. Neurol. 501:866–878, 2007. © 2007 Wiley‐Liss, Inc.
Morphological sex differences and laterality in the prepubertal medial amygdala
Authors: Cooke Bradley M. , Stokas Michael R. , Woolley Catherine S.
Published: February 2007

The medial amygdala (MeA) is crucial in the expression of sex‐specific social behaviors. In adult rats the regional volume of the MeA posterodorsal subnucleus (MeApd) is ≈50% larger in males than in females. The MeApd is also sexually dimorphic in prepubertal rats. We have recently shown that the left MeApd is significantly larger in prepubertal males than females. In contrast with volumetric sex differences elsewhere in the brain, however, we found no sex difference in the number of left MeApd neurons. In the present study we investigated the cellular bases of the sex difference in MeApd regional volume by quantifying the volume occupied by dendrites, axons, synapses, or glia, and by measuring MeApd dendritic morphology in 26–29‐day‐old male and female rats. We find that the volume occupied by dendritic shafts and glia completely accounts for the sex difference in left MeApd regional volume. Dendritic length measurements in the left hemisphere confirm that males have greater overall dendritic length, which is due to greater branching rather than to longer dendrite segments. In the right hemisphere the pattern of sex differences was different: Males have more MeApd neurons than females, whereas the dendritic morphology of individual neurons is not sexually dimorphic. These results highlight the importance of evaluating laterality in the MeA and suggest that the left and right MeA could play different roles in neuroendocrine regulation and sexually dimorphic social behaviors. J. Comp. Neurol. 501:904–915, 2007. © 2007 Wiley‐Liss, Inc.
CD4+ T lymphocytes enumeration by an easy‐to‐use single platform image cytometer for HIV monitoring in resource‐constrained settings
Authors: Li Xiao , Ymeti Aurel , Lunter Björn , Breukers Christian , Tibbe Arjan G.J. , Terstappen Leon W.M.M. , Greve Jan
Published: February 2007

Background:

HIV monitoring in resource‐constrained settings demands affordable and reliable CD4+ T lymphocytes enumeration methods. We developed a simple single platform image cytometer (SP ICM), which is a dedicated volumetric CD4+ T lymphocytes enumeration system that uses immunomagnetic and immunofluorescent technologies. The instrument was designed to be a low‐cost, yet reliable and robust one. In this article we test the instrument and the immunochemical procedures used on blood from HIV negative and HIV positive patients.

Methods:

After CD4 immunomagnetic labeling in whole blood, CD4+ T lymphocytes, CD4+dim monocytes and some nonspecifically labeled cells are magnetically attracted to an analysis surface. Combining with CD3‐Phycoerythrin (PE) labeling, only CD3+CD4+ T lymphocytes are fluorescently labeled and visible in a fluorescent image of the analysis surface. The number of CD4+ T lymphocytes is obtained by image analysis. Alternatively, CD3 immunomagnetic selection in combination with CD4 immunofluorescent labeling can also be applied for CD4+ T lymphocytes enumeration.

Results:

The SP ICM system was compared with two single platform flow cytometer (SP FCM) methods: tetraCXP and TruCount methods. The SP ICM system has excellent precision, accuracy and linearity for CD4+ T lymphocytes enumeration. Good correlations were obtained between the SP ICM and the SP FCM methods for blood specimens of 44 HIV− patients, and of 63 HIV+ patients. Bland–Altman plots showed interchangeability between the SP ICM and the SP FCM methods.

Conclusions:

The immunolabeling methods and the instrumentation are simple and easy‐to‐handle for less‐trained operators. The SP ICM system is a good candidate for CD4+ T lymphocytes enumeration in point‐of‐care settings of resource‐constrained countries. © 2007 Clinical Cytometry Society.
Zu den Neuerungen der DIN 1053‐100 und zur Gültigkeit der DIN 1053‐1
Authors: Jäger Wolfram
Published: February 2007

Mit der DIN 1053‐100 geht der Mauerwerksbau auch in Deutschland auf das semiprobabilistische Sicherheitskonzept über. Die wesentlichen Neuerungen werden kurz erläutert, nachdem im Heft 5/2006 eine komplexe Darstellung der Ausarbeitung dieser Norm gegeben worden ist. Ausführung und Konstruktion bleiben weiter nach DIN 1053‐1 geregelt. Sie ist daher nach wie vor eine eingeführte Technische Baubestimmung und kann auf der Basis des globalen Sicherheitskonzeptes wie bisher angewendet werden, wenn dies gewünscht ist.
DGfM: Mauerwerk 1/2007
Authors: Rast Ronald
Published: February 2007

Planungssicherheit für Architekten und Ingenieure bei Anwendung der DIN 1053‐1:1996‐11 “Mauerwerk – Teil 1: Berechnung und Ausführung” bleibt auch nach Einführung der neuen Normenreihe DIN 1055 “Einwirkungen auf Tragwerke” zum 01.01.2007 per Stichtagsregelung ohne Einschränkung erhalten

Wenig Weitsicht im Umweltbundesamt

Neues Vorstandsmitglied im Amt bestätigt

DGfM‐Newsletter: Bereich Markt; Bereich Technik; Aktuell; Termine
A role for eukaryotic translation initiation factor 2B (eIF2B) in taste memory consolidation and in thermal control establishment during the critical period for sensory development
Authors: Tirosh Sharon , Elkobi Alina , Rosenblum Kobi , Meiri Noam
Published: February 2007

All species exhibit critical periods for sensory development, yet very little is known about the molecules involved in the changes in the network wiring that underlies this process. Here the role of transcription regulation of the translation machinery was determined by evaluating the expression of eIF2Bε, an essential component of translation initiation, in both taste‐preference development and thermal control establishment in chicks. Analysis of the expression pattern of this gene after passive‐avoidance training revealed clear induction of eIF2Bε in both the mesopallium intermediomediale (IMM) and in the striatum mediale (StM). In addition, a correlation was found between the concentration of methylanthranilate (MeA), which was the malaise substrate in the passive‐avoidance training procedure, the duration of memory, and the expression level of eIF2Bε. Training chicks on a low concentration of MeA induced short‐term memory and low expression level of eIF2Bε, whereas a high concentration of MeA induced long‐term memory and a high expression level of eIF2Bε in both the IMM and StM. Furthermore, eIF2Bε‐antisense “knock‐down” not only reduced the amount of eIF2Bε but also attenuated taste memory formation. In order to determine whether induction of eIF2Bε is a general feature of neuronal plasticity, we checked whether it was induced in other forms of neuronal plasticity, with particular attention to its role in temperature control establishment, which represents hypothalamic‐related plasticity. It was established that eIF2Bε‐mRNA was induced in the preopotic anterior hypothalamus during heat conditioning. Taken together, these results correlate eIF2Bε with sensory development. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007.
A study on high‐efficiency short‐wave AM transmitter
Authors: Yamazoe Masahiko , Haeiwa Kazuhisa , Wakai Kazuaki , Kakutani Tomohide
Published: February 2007

In a short‐wave (3 to 30 MHz) high‐power transmitter, the modulation section is fabricated with semiconductors, but the total semiconductor realization including the final‐stage PA is difficult and has not been accomplished to date. The authors' objective is to achieve total use of semiconductors for realization of a 100‐kW‐class short‐wave high‐power transmitter. An optimal power device (MOSFET) to obtain high efficiency is selected. In addition, a circuit for realization of high efficiency and a synthesis method for excellent linearity are proposed. In the short‐wave band, there is a problem of increased loss due to parasitic diodes for the digital‐processing AM modulation device used in the middle‐frequency range. It is shown that the method cannot be applied directly. Further, an optimum modulation format and a circuit configuration for realization of a short‐wave high‐efficiency AM transmitter are proposed. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(3): 33–41, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20283
Rectangular waveguide compatible NRD guide gunn oscillator with medium power and low phase noise at 60 GHz
Authors: Kuroki Futoshi , Yamaoka Ko‐Ichi , Shimoi Hiroshi , Yoneyama Tsukasa
Published: February 2007

A 60‐GHz frequency‐stabilized small oscillator consisting of a Gunn diode, a circulator, and a matched termination is fabricated by using NRD guides. The emphasis in this paper is adaptability to a rectangular waveguide circuit. To this end, an NRD guide–waveguide transition is designed. In the 60‐GHz NRD Gunn diode oscillators to date, Gunn diodes sealed in a package dedicated to the NRD guide have been placed on special order. With a view to cost reduction, a Gunn diode mount is conceived in which a general‐purpose‐type Gunn diode can be used. The oscillation output of the fabricated oscillator is 13 dBm and the phase noise at 300 kHz offset is −113 dBc/Hz. Further, the frequency variation due to ambient temperature change is −1.3 ppm/°C so that the fabricated millimeter‐wave oscillator is highly stable, with medium power output and low noise. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(3): 26–32, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20290
A study on two‐stage self‐organizing map and its application to clustering problems
Authors: Kato Satoru , Koike Kenta , Horiuchi Tadashi
Published: February 2007

This paper presents a two‐stage self‐organizing map algorithm that we call two‐stage SOM which combines Kohonen's basic SOM (BSOM) and Aoki's SOM with threshold operation (THSOM). In the first stage of two‐stage SOM, we use BSOM algorithm in order to acquire topological structure of input data, and then we apply THSOM algorithm so that inactivated code vectors move to appropriate region reflecting the distribution of the input data. Furthermore, we show that two‐stage SOM can be applied to clustering problems. Some experimental results reveal that two‐stage SOM is effective for clustering problems in comparison with conventional methods. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(1): 46–53, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20268
An agent‐based scheduling method enabling rescheduling with trial‐and‐error approach
Authors: Mitsui Hiroyasu , Sugihara Hiroaki , Koizumi Hisao , Sawamoto Jun , Tsuji Hidekazu
Published: February 2007

Scheduling optimization is an extremely difficult problem; therefore, many scheduling methods such as linear programming or stochastic searching have been investigated in order to obtain better solutions close to the optimum one. After obtaining a certain solution, scheduling managers may need to reschedule another solution that corresponds to changes in requirements or resources. However, rescheduling problems become more difficult as they become larger in scale. In this paper, we propose an agent‐based rescheduling system using the linear programming approach. In our system, agents can autonomously conduct rescheduling on behalf of managers by repeated trial and error in balancing loads or changing the priority of resource allocation until it reaches a better solution for the requirement is obtained. In addition, managers can engage in trial and error with the help of agents to seek a better solution by changing constraint conditions. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(1): 26–38, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20434
On a stability of minimum variance control
Authors: Mori Yasuchika , Asami Futoshi
Published: February 2007

Self‐tuning control (STC) is a control technique to adjust the parameter of the on‐line controller which adapts itself when plant parameter changes. Effective ways to design STC include minimum‐variance control (MVC), generalized minimum‐variance control (GMVC), and generalized predicted control (GPC). The structure of MVC and GMVC is especially easy and manageable. It is necessary to use MVC so that a plant is a minimum phase system and stable in the discrete time‐domain. But, in general the actual controlled system is in continuous time. Then, when digitizing is performed, it sometimes becomes a non‐minimum phase system. If we set the sampling time very low, an MVC controller has unstable poles. In this paper, we propose an MVC design for a plant which is stable and a minimum phase system in a continuous time domain by introducing a delta operator and weight adjustment of the cost function. Then, we evaluate its stability. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(1): 17–25, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20472
CE chips fabricated by injection molding and polyethylene/thermoplastic elastomer film packaging methods
Authors: Huang Fu‐Chun , Chen Yih‐Far , Lee Gwo‐Bin
Published: February 2007

This study presents a new packaging method using a polyethylene/thermoplastic elastomer (PE/TPE) film to seal an injection‐molded CE chip made of either poly(methyl methacrylate) (PMMA) or polycarbonate (PC) materials. The packaging is performed at atmospheric pressure and at room temperature, which is a fast, easy, and reliable bonding method to form a sealed CE chip for chemical analysis and biomedical applications. The fabrication of PMMA and PC microfluidic channels is accomplished by using an injection‐molding process, which could be mass‐produced for commercial applications. In addition to microfluidic CE channels, 3‐D reservoirs for storing biosamples, and CE buffers are also formed during this injection‐molding process. With this approach, a commercial CE chip can be of low cost and disposable. Finally, the functionality of the mass‐produced CE chip is demonstrated through its successful separation of ϕX174 DNA/HaeIII markers. Experimental data show that the S/N for the CE chips using the PE/TPE film has a value of 5.34, when utilizing DNA markers with a concentration of 2 ng/μL and a CE buffer of 2% hydroxypropyl‐methylcellulose (HPMC) in Tris‐borate‐EDTA (TBE) with 1% YO‐PRO®‐1 fluorescent dye. Thus, the detection limit of the developed chips is improved. Lastly, the developed CE chips are used for the separation and detection of PCR products. A mixture of an amplified antibiotic gene for Streptococcus pneumoniae and ϕX174 DNA/HaeIII markers was successfully separated and detected by using the proposed CE chips. Experimental data show that these DNA samples were separated within 2 min. The study proposed a promising method for the development of mass‐produced CE chips.
Fast establishment of single‐strand conformation polymorphism by targeted primer development in Pityogenes chalcographus (Coleoptera, Scolytinae)
Authors: Arthofer Wolfgang , Avtzis Dimitrios N. , Stauffer Christian
Published: February 2007

SSCP is a widespread method for mutation detection in biomedical research. Yet, its potential as a tool for population genetics is still not fully utilized. Based on mitochondrial DNA sequences of 96 specimens of the wood‐boring beetle Pityogenes chalcographus we constructed a phylogenetic tree of European populations. This tree consisted of six broadly sympatric diverged lineages containing in total 34 haplotypes. Genetic regions of high mutational activity were determined and used for targeted SSCP primer development. In an SSCP mass screening of 427 individuals more than 80% could be assigned to a distinct clade, revealing the insect's genetic structure in Europe. It was demonstrated that analysis of known sequences allows the setup of a functional SSCP protocol within less than two weeks of working time and that phylogenetic data may be retrieved with high accuracy and significantly reduced costs compared to direct sequencing of PCR products.
Sensitivity of drosophila melanogaster to low concentrations of the gaseous 1, 2‐dibromoethane: I. Acute exposures
Authors: Kale P. , Baum J. W.
Published: February 2007

Drosophila melanogaster males were exposed to gaseous 1, 2‐dibromoethane at concentrations lower than those used in aerosol treatments of suspected mutagens by other investigators. Premeiotic stages appear to be more sensitive than postmeiotic stages to gaseous mutagens. At an exposure of 125 ppm.hr, significant numbers of mutations were induced in spermatids, spermatocytes, and spermatogonia. Since this exposure increased the mutation rate in spermatogonial stages by a factor of 20–40 over the spontaneous rate, it appears that the lowest detectable exposures may be much lower than 125 ppm.hr for 1, 2‐dibromoethane.
Genetic effects of pr toxin in eukaryotic microorganisms
Authors: Wei Ru‐Dong , Ong Tong‐Man , Whong Wen‐Zong , Frezza Domenico , Bronzetti Giorgio , Zeiger Errol
Published: February 2007

The genetic activity of PR toxin, a mycotoxin from Penicillium roqueforti, was studied in Saccharomyces cerevisiae and Neurospora crassa. The results show that PR toxin, without enzymic activation, causes gene conversion in S. cerevisiae strains D4 and D7, reverse mutation in S. cerevisiae strain D7 and N. crassa strain N24, and mitotic crossing‐over in S. cerevisiae strain D7, In the log phase cells of S. cerevisiae the effects are more pronounced at alkaline than at acid pH. The active site responsible for the genetic activity and toxicity is known. The carbonyl groups appear to play an important role in the biologic activity of this molecule.
Mutagens in a river heavily polluted with paper recycling wastes: Results of field and laboratory mutagen assays
Authors: Klekowski Ed , Levin David E.
Published: February 2007

Paper recycling industries generate considerable quantities of waterborne wastes, and thus water pollution constitutes the greatest environmental problem associated with this industrial activity [Hunt and Franklin, 1973]. Generally the impact of this water pollution is considered in terms of aesthetic blight and deterioration of water quality. We present data that document another aspect of this pollution, the environmental contamination of an aquatic ecosystem with mutagenic materials.

A natural population of the fern Osmunda regalis growing in a river heavily polluted with paper recycling wastes had a high incidence of chromosome mutations. This population was monitored for four years for the frequency of two‐break chromosome mutations. These mutations were postzygotic in origin and suggested the presence of mutagens in the river water. The fern population is downstream from the outfalls of a paper recycling mill, which was discharging 13.3 ± 106 liters of untreated paper recycling waste per day.

In 1977 a waste‐water‐treatment facility was constructed to remove the solid waste previously discharged into the river. This facility generates 69,300 kg of solid waste daily, which is taken to a landfill. Periodic samples of this solid waste were collected from the waste‐treatment facility in the summer of 1978, extracted with various solvents, and the extracts tested for mutagenic activity with the Salmonella/mammalian microsome mutagenicity test [Ames et al, 1975]. A majority of the solid waste samples contained mutagenic materials, but in all cases S‐9 activation was required for mutagenic activity. The samples also were assayed with the soybean mitotic crossing‐over assay [Vig, 1975]. Four out of six samples were positive.

These results document the presence of mutagens in the solid waste generated by a paper recycling industry and the genetic impact of these mutagens on the local biota.
Dominant lethality in frog embryos after paternal treatment with triethylenemelamine: Cytogenetics, morphology, and swimming capability
Authors: McKinnell Robert G. , Picciano Dante J. , Schaad John W.
Published: February 2007

Male frogs (Rana pipiens) were injected intraperitoneally with triethylenemel‐amine (TEM). The injected males were held for seven days to permit TEM interaction with sperm. The TEM‐treated males were then spermiated with human chorionic gonadotropin (HCG) and the ova of normal females were inseminated with the sperm. Direct observation was made of in vitro fertilized ova, cleavage, blastulation, and subsequent embryonic development. No differences were detected between the controls and treated animals from any experimental group for fertilization, cleavage, and blastulation. Dose‐related morphologic abnormalities first became apparent at the time of gastrulation; the capability of hatched embryos to swim was affected by TEM. Metaphase chromosomes were studied from randomly selected embryos, and the prevalence of chromosomal structural abnormalities increased with dose over a range of 13–1,300 μg TEM per kilogram frog.
Cytogenetic effects of busulfan in vivo on bone marrow cells and oocytes of adult mice and liver cells of transplacentally exposed embryos
Authors: Basler A. , Theiss I. , Röhrborn G.
Published: February 2007

Adult female mice were twice treated orally with 15, 30, or 60 mg busulfan per kg of body weight. In bone marrow, a dose‐dependent linear increase in the frequency of chromosome aberrations was observed. Similar to the effects of other alkylating agents, busulfan induced all types of aberrations, including exchanges.

In metaphase II oocytes, only a few chromosome aberrations were observed. An intervening round of DNA‐replication seems to be necessary to translate busulfan‐induced lesions in oocytes into chromosome aberrations.

In embryonic liver cells of transplacentally exposed mice, chromosome aberrations were induced.
Lack of correlation between mms‐toxicity in larvae and in adults of mutagen‐sensitive mutants of drosophila melanogaster
Authors: Graf U. , Würgler F. E.
Published: February 2007

Adult males of 20 different stocks of Drosophila melanogaster, including 16 with various X‐linked mutagen‐sensitive mutations, were tested for sensitivity to the lethal action of methyl methane sulfonate (MMS) in a continuous feeding experiment. It was impossible to establish a correlation between MMS‐toxicity in adults and MMS‐toxicity in larvae. In addition, experiments to examine the fertility of MMS‐treated flies of four mutagen‐sensitive strains and one wild‐type strain were performed. These experiments demonstrated that the spermatogonia of mei‐9L1 and mei‐41D5 in larvae and in adults are more sensitive to MMS than the spermatogonia of the wild‐type strain or the other two mutagen‐sensitive strains.
Mutagenic activity of epoxy embedding reagents employed in electron microscopy
Authors: Murray Mary P. , Cummins Joseph E.
Published: February 2007

Components of epoxy‐based embedding media used in electron microscopy were examined for their mutagenicity in the Ames Salmonella system. The compounds, singly and in combination, were shown to be active with strain TA100 (base substitution indicator) but not with TA98 (frameshift indicator). When tested separately the epoxy resins Araldite, Epon, and vinyl cyclohexen dioxide (VCD) and the plasticizer diglycidyl ether of propylene glycol (DER‐736) were found to be significantly mutagenic. These active compounds, in combination with liver mixed oxidase preparation (S9), showed increased mutagenicity over similar preparations in the absence of microsomal activation.
Phototherapy for neonatal hyperbilirubinemia—a potential environmental health hazard to newborn infants: A review
Authors: Speck William T. , Rosenkranz Herbert S.
Published: February 2007

Phototherapy has been shown to be an effective therapy for severe neonatal jaundice. However, because of its seemingly innocuous effect on normal babies, this therapeutic modality has been widely used to prevent jaundice in circumstances where it may be neither necessary nor beneficial. The present report summarizes results which indicate that phototherapy is endowed with DNA‐modifying properties and has therefore the potential for inducing genetic and carcinogenic effects. These disconcerting findings concerning the long‐term hazardous consequences of an accepted therapeutic procedure require that the unique physiologic and pharmacologic characteristics of the newborn populations be recognized when assessing the risks and benefits of phototherapy.
Regulation of dimethylnitrosamine metabolism by androgenic hormones
Authors: Bakshi K. , Brusick D. , Bullock L. P. , Bardin C. W.
Published: February 2007

Hormonal regulation of dimethylnitrosamine (DMN) metabolism by mouse kidney microsomes was investigated using an in vitro mutagenesis system that detects bioactive metabolites of this procarcinogen by measuring reverse mutation in Salmonella typhimurium his auxotrophs. Induction of microsomal DMN metabolizing enzymes was androgen‐specific. Testosterone and medroxyprogesterone acetate were active inducers, d/1 norgestrel was less active, while epitestosterone, estradiol, and progesterone were ineffective. The response to testosterone and medroxyprogesterone acetate was time‐ and dose‐dependent. Eleven strains of inbred mice were screened for their response to exogenous testosterone. DMN metabolism was stimulated in all mouse strains except for RF/J mice. Other androgenic end points were responsive in the latter strain, however.

These observations suggest that induction of renal microsomal DMN metabolising enzymes is androgen‐specific and probably mediated via the androgen receptor. The insensitivity of RF/J mice may be due to a mutation affecting a key step in the enzymatic activation of DMN.
Mitotic arrest by benzimidazole analogs in human lymphocyte cultures
Authors: Holden Henry E. , Crider Paula A. , Wahrenburg Margitta G.
Published: February 2007

Published reports have suggested the possible association of mutagenic or teratogenic properties of some benzimidazole analogs with induced spindle disruption and consequent mitotic arrest. Studies were conducted to explore this correlation. Seven benzimidazole analogs were evaluated in a human lymphocyte system for ability to block mitosis at metaphase. Confirming the previously reported results, four compounds, mebendazole, parbendazole, cambendazole, and fenbendazole, caused metaphase accumulation, which we found to be dose and time‐related. Minimum effective dose for mebendazole and cambendazole was 10 μg/ml; for parbendazole, 1 μg/ml; and for fenbendazole, 100 μ/ml. The drug‐induced mitotic arrest is qualitatively and quantitatively similar to that produced by colcemid. No activity was observed with three other compounds, benzimidazole, thiabendazole, and oxfendazole when tested at 100 μg/ml. Presence or absence of mitotic effects is correlated with reported teratogenicity with five out of the seven analogs. This suggests some utility of mitotic assessments for predicting teratogenicity.
In vitro induction of segregational errors of chromosomes by natural cannabinoids in normal human lymphocytes
Authors: Henrich Richard T. , Nogawa Takayuki , Morishima Akira
Published: February 2007

It has been shown that segregational errors (SE) of chromosomes can be induced by olivetol and several halogenated inhalation anesthetics. The purpose of this study was to examine the effects of natural cannabinoids — including delta‐9‐tetrahydrocannabinol (THC), cannabinol (CBN), and cannabidiol (CBD) — on chromosome segregation.

Lymphocytes obtained from healthy adult males were incubated with various concentrations of natural cannabinoids for 72 hours. Anaphase preparations were made from these cultures. A statistically significant increase in the incidence of SE of chromosomes was observed in the lymphocytes exposed to THC at a concentration of 3.2 × 10−6 M, but not to CBN or CBD. A greater incidence of bridge formations, anaphase lags, micronuclei, and unequal segregations in bipolar divisions and multipolar divisions were observed in THC‐treated lymphocytes, compared with the controls. However, only anaphase lags and unequal segregations in bipolar divisions reached statistically significant levels. It appears that THC affects the formation of microtubules and spindles and may be considered as a mitotic poison. The value of examining SE as a part of cytogenetic studies on chemical mutagens is emphasized. A description of a classification system of SE developed in our laboratory is also presented. This system can be applied to studies using both normal human lymphocyte cultures and lymphoid cell lines.
Induction of chromosome shattering and micronuclei by ultraviolet light and caffeine. I. Temporal relationship and antagonistic effects of the four deoxyribonucleosides
Authors: Cremer C. , Cremer T. , Simickova M.
Published: February 2007

It is known that nucleosides may have antimutagenic and anticlastogenic effects. Here, we have investigated the influence of nucleosides on the induction of shattered chromosomes (fragmentation and/or pulverization of chromosomes of a mitotic cell) and of micronuclei by ultraviolet (UV) light and caffeine. Asynchronous cell cultures of a V79 subline of the Chinese hamster were irradiated at wavelength 254 nm using fluences up to 5.2 joules/m2. Following irradiation, the cells were postincubated either with 1.0 mM or 2.0 mM caffeine alone or with caffeine plus the four deoxyribonucleosides (dXs) (concentration 0.1 mM each). After different incubation times (three to 24 hours), chromosome preparations were performed. In other experiments, synchronized cells were used. The percentage of metaphase spreads with shattered chromosomes and the percentage of cells with micronuclei were determined. Post‐treatment with caffeine alone resulted in shattered chromosomes in a high percentage of cells at the first post‐irradiation mitosis as described previously. Formation of cells with micronuclei was observed only after the appearance of mitotic cells with shattered chromosomes, the maximum percentage of cells with micronuclei being smaller than the maximum percentage of cells with shattered chromosomes. The strong potentiating effect of UV‐ light plus caffeine was significantly reduced, however, if the post‐treatment was performed with caffeine plus nucleosides. A significant reduction was also observed in the percentage of micronuclei. An evaluation of the mitotic indices and of cell‐cycle parameters indicates that the effect of nucleosides was not due to enhanced interphase death.
Absence of arsenite mutagenicity in E coli and chinese hamster cells
Authors: Rossman T. G. , Stone D. , Molina M. , Troll W.
Published: February 2007

Because exposure to compounds of arsenic has been implicated as a cause of cancer, an investigation of the mutagenicity of sodium aresenite in E coli and in Chinese hamster cells was performed. In the E coli system, Trp revertants were not induced by arsenite in a variety of experimental protocols including spot tests, treat and plate protocols, and fluctuation tests. The mutator effect of a tif‐1 strain was partially blocked by arsenite. Arsenite did not cause the induction of λ prophage. In Chinese hamster cells, arsenite did not induce ouabain‐resistant mutants or thioguanine‐resistant mutants. We conclude that arsenite is not mutagenic to E coli or to Chinese hamster cells. When added to the plating medium, arsenite can act as an anti‐mutagen by inhibition of induction of the error‐prone SOS repair system in E coli.
Use of hydroxyurea in the measurement of DNA repair by the BND cellulose method
Authors: Irwin James , Strauss Bernard
Published: February 2007

Hydroxyurea inhibition is a convenient method of suppressing replicative DNA synthesis for DNA excision‐repair measurement by the BND cellulose technique. Nonetheless, hydroxyurea can introduce artefacts by direct reaction with repair‐inducing compounds and by long‐term inhibition of the overall repair process. A simple technique of overcoming these problems is described. Cells are reacted with repair‐inducing compounds in the absence of hydroxyurea, the cells are washed free of inducer, hydroxyurea is added to 2 mM, and after a short period to establish replication inhibition, 3H dThd is added and repair measured over a one‐hour incubation period.
Mutagenicity tests of fabric‐finishing agents in salmonella typhimurium: Fiber‐reactive wool dyes and cotton flame retardants
Authors: MacGregor James T. , Diamond Martin J. , Mazzeno Laurence W. , Friedman Mendel
Published: February 2007

Thirty‐nine fabric‐finishing agents were tested for mutagenic activity in Salmonella typhimurium. Twenty‐four fiber‐reactive wool dyes and three acid dyes (not fiber‐reactive) were screened by spot tests in strains TA100, TA98, TA1535, and TA1537. Among these dyes, seven bromoacrylamide dyes and one vinyl sulfone dye were mutagenic. Additionally, one of the three acid dyes was mutagenic in spot tests. The mutagenicity of the acid dye was due to an impurity or breakdown product rather than to the dye itself; the origin of the activities of the other dyes is unknown. No mutagenicity was observed among five chlorotriazine or four sulfonyl‐ethane sulfonic acid dyes. Eight phosphorus‐containing flame retardants (phosphonium, phosphine, phosphine oxide, and phosphonic acid derivatives) and methyl‐N‐methylolcarbamate, which is employed to obtain a flame‐retardant finish on cotton, were tested for mutagenicity in strains TA100, TA98, TA1535, and TA1537, using quantitative incorporation assays. All were nonmutagenic. Two of three bromoalkyl‐substituted triazine flame retardants were mutagenic in strains TA100 and TA1535. It is unknown whether this activity is due to impurities or to the parent compound. The flame retardants tested were either in actual commercial use or in experimental development for potential commercial processes. These results indicate the need for early testing of potential fabric‐finishing agents and processes.
X‐ray‐induced chromosome aberrations in down lymphocytes: An explanation of their increased sensitivity
Authors: Preston R. Julian
Published: February 2007

Unstimulated lymphocytes from individuals with Down Syndrome (trisomy 21) are more sensitive to the induction of dicentric and ring aberrations by X rays than normal lymphocytes. Several explanations involving the more rapid rejoining of X‐ray–induced lesions in Down cells have been offered. It is shown here that the repair of the DNA damage converted into chromosome aberrations is more rapid in Down cells than normal cells. This more rapid repair results in a higher probability of producing chromosome aberrations, and hence higher aberration frequencies in Down than normal cells.
Increased cytotoxicity and mutagenicity of diesel fuel after reaction with NO2
Authors: Henderson Thomas R. , Li A. P. , Royer Robert E. , Clark Charles R.
Published: February 2007

Gas chromatography/mass spectrometry (GC/MS) of diesel fuel aromatics detected polynuclear aromatic hydrocarbons from naphthalenes to phenanthrenes, but no four‐ or five‐ring aromatics. This aromatic fraction treated with NO2 was found to contain nitro‐aromatics, but only the naphthalene and biphenyl nitro‐aromatics were detectable by direct GC/MS. By reduction of the nitro groups to amines, diazotization and reduction to yield aryl‐iodides, it was possible to demonstrate that nitro‐derivatives of most of the starting aromatics were present after NO2‐treatment. Diesel fuel was separated into aliphatic and aromatic fractions by extraction with dimethyl sulfoxide. These fractions were devoid of mutagenic activity in the Ames bioassay and exhibited low cytotoxicity to CHO cells in culture. However, after reaction with NO2, the products contained frameshift mutagens which did not require activation by S‐9 microsomal enzymes. The biological activity of the NO2‐treated aromatic fraction from fuel was more than 40 times greater in Salmonella TA100 than fuel aliphatics treated with NO2. The LC50 to CHO cells in culture increased more than fivefold for aromatics and more than tenfold for aliphatics. Similar to the diesel exhaust particulate extract, the cytotoxicity of the nitrated fractions was decreased by serum and glutathione. Reaction of fuel aromatics with NO2 may be one mechanism which contributes to the formation of cytotoxic and mutagenic activities in diesel exhaust.
Mutagenicity of coal fly ash: A new bioassay for mutagenic potential in a particle feeding ciliate
Authors: Smith‐Sonneborn J. , Palizzi R. A. , Herr C. , Fisher G. L.
Published: February 2007

The use of the established mutagenesis assay in Paramecium as a prescreen for hazardous environmental particles is described. Since these protozoans ingest particles of the size respired by animals and man, the biological effects of the respirable fraction of fly ash particles were monitored in particle‐feeding eukaryotic cells. Fly ash from coal combustion was utilized for these studies and was found to be mutagenic. The effects of physical and chemical treatment of the particle mutagenicity provided evidence for both heat‐stable, heat‐labile and acid extractable mutagenic agents.
The mutagenic and SOS‐inducing potential of the soluble organic fraction collected from diesel particulate emissions
Authors: Dukovich M. , Yasbin R. E. , Lestz S. S. , Risby T. H. , Zweidinger R. B.
Published: February 2007

Studies involving the Ames Salmonella mutagenicity test and the Bacillus subtilis comptest have demonstrated that the soluble organic fraction of diesel particulate is potentially mutagenic and DNA damaging. The soluble organic fraction was extracted from exhaust particulate samples collected from four different diesel engines operated at specified conditions. For each fraction collected, an increase in the concentration of the organic material resulted in a subsequent increase in the number of histidine prototrophs obtained when this material was added to the histidine auxotrophic strains that comprise the Ames Salmonella test. Specifically, the number of induced revertants, for strains TA98 and TA100, ranged from less than one revertant per μg of sample to 29 revertants per μg of sample. The ability of these organic fractions to induce bacterial SOS functions also was determined by exposing competent cultures of Bacillus subtilis strain RUB827 to increasing concentrations of these extracts. With varying efficiencies, these samples were positive in their ability to induce the SOS system of B subtilis. Significantly, the toxicity of these mutagenic and DNA damaging samples never resulted in more than 95% killing, even for the highest concentrations tested in the Salmonella and B subtilis assay.
Mutagenicity of the mycotoxin botryodiplodin in the salmonella typhimurium/microsomal activation test
Authors: Moulé Yvonne , Decloitre Françoise , Hamon Gérard
Published: February 2007

Botryodiplodin, a mycotoxin synthesized by some strains of Penicillium roqueforti was tested for lethal and mutagenic effects on Salmonella typhimurium (TA98). Botryodiplodin was active in the histidine reversion system without metabolic activation.
The use of adult rat liver cultures in the detection of the genotoxicity of various polycyclic aromatic hydrocarbons
Authors: Tong C. , Laspia M. F. , Telang S. , Williams G. M.
Published: February 2007

The hepatocyte primary culture (HPC)‐DNA repair test and the adult rat liver epithelial cell (ARL)—hypoxanthine‐guanine phosphoribosyl transferase (HGPRT) mutagenesis assay are two in vitro short‐term tests that possess intrinsic capability for xenobiotic biotransformation. Both assays detected the genotoxicity of a variety of carcinogenic polycyclic aromatic hydrocarbons. Thus, these two tests, which embody intact cellular metabolism, are useful for the evaluation of this class of carcinogens and provide results that strengthen those obtained in tests dependent upon subcellular metabolism.