bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties of Some Alkyl Substituted Phthalocyanines and Related Macrocycles
Authors: Cook Michael J.
Published: October 2002

This report provides an account of research undertaken at the University of East Anglia, United Kingdom, into phthalocyanine derivatives substituted at six or more of the nonperipheral sites by alkyl groups. When first prepared they were only the second series of substituted phthalocyanines known to exhibit columnar liquid crystal behaviour. The compounds also form structured films by the spin‐coating technique, a formulation with potential for FET devices. The zinc metallated derivatives are photosensitisers of singlet oxygen and show good potential for applications in photodynamic therapy. A mixed cyclotetramerisation of a 3,6‐dialkylphthalonitrile with a second aromatic dinitrile forms so‐called 3 : 1 phthalocyanines in which three of the benzenoid rings are substituted with two alkyl groups and the fourth is substituted differently. Appropriate substituents provide amphiphilic compounds that form well‐ordered films by the Langmuir‐Blodgett method and self‐assembly techniques. Characterisation of the films using a variety of methods is discussed and applications described. Examples of 3 : 1 phthalocyanine‐like macrocycles in which one of the benzenoid rings is replaced by a heterocycle extend the range of properties exhibited. These include broadband absorption in the near infrared and, in particular cases, edge‐to‐face dimerisation through coordination of a pyridine nitrogen to a zinc centre in a second macrocycle. The potential for using suitably functionalised 3 : 1 phthalocyanines as building blocks for more complex structures such as liquid crystalline main‐chain polymeric phthalocyanines and phthalocyanino‐dehydroannulenes is described. © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc., Chem Rec 2: 225–236, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10028
Using a cross section to train veterinary students to visualize anatomical structures in three dimensions*
Authors: Provo Judy , Lamar Carlton , Newby Timothy
Published: October 2002

A cross section was used to enhance three‐dimensional knowledge of anatomy of the canine head. All veterinary students in two successive classes (n = 124) dissected the head; experimental groups also identified structures on a cross section of the head. A test assessing spatial knowledge of the head generated 10 dependent variables from two administrations. The test had content validity and statistically significant interrater and test–retest reliability. A live‐dog examination generated one additional dependent variable. Analysis of covariance controlling for performance on course examinations and quizzes revealed no treatment effect. Including spatial skill as a third covariate revealed a statistically significant effect of spatial skill on three dependent variables. Men initially had greater spatial skill than women, but spatial skills were equal after 8 months. A qualitative analysis showed the positive impact of this experience on participants. Suggestions for improvement and future research are discussed. © 2002 John Wiley & Sons, Inc. J Res Sci Teach 39: 10–34, 2002
Biomarker study of a municipal effluent dispersion plume in two species of freshwater mussels
Authors: Gagné F. , Blaise C. , Aoyama I. , Luo R. , Gagnon C. , Couillard Y. , Campbell P. , Salazar M.
Published: October 2002

The toxicological effects of a primary‐treated municipal effluent plume were investigated in two species of freshwater mussels, Elliptio complanata and Dreissena polymorpha, exposed for 62 days at sites upstream and downstream of an effluent outfall in the St. Lawrence River (Quebec, Canada). Levels of metallothioneins (MT), cytochrome P4501A1 activity, DNA damage, total lipids, relative levels of vitellins, and phagocytic activity (in E. complanata hemocytes) were determined after the exposure period. A parallel analysis measured heavy metals and coprostanol in mussel tissues. The results show that significant levels of coprostanol and some metals (specifically, Cu, Hg, Sb, Se, and Zn) had accumulated in mussels caged 5 km downstream of the effluent plume. Mixed‐function oxidase activity, MT in gills, total lipids, DNA damage (in D. polymorpha only), and total hemolymph bacteria (in E. complanata only) had increased in these mussels, while levels of total cadmium (Cd), MT in digestive glands or whole soft tissues, phagocytic activity, and DNA damage in the digestive gland (in E. complanata only) were diminished. The exposure of mussels to surface waters contaminated by a municipal effluent led to many stress responses, depending on both the tissues and the species being examined. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 149–159, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10046
Increased metal bioavailability following alteration of freshwater dissolved organic carbon by ultraviolet B radiation exposure
Authors: Winch Susan , Ridal Jeffrey , Lean David
Published: October 2002

Dissolved organic carbon (DOC) is critically important in the chemistry of freshwater. It complexes heavy metals, making them less bioavailable to aquatic organisms, and absorbs and attenuates UVB radiation, undergoing degradation and alteration in the process. This study examined changes in metal toxicity to the freshwater green alga Pseudokirchneriella subcapitata in high‐ and low‐DOC natural water samples after exposure to UVB radiation. Brown‐water and clear‐water samples were irradiated for 0, 5, and 10 days. The DOC concentrations of the samples were measured, and they were subsequently spiked with Cu, Ni, Zn, Cd, Co, and Pb and used in algal bioassays to measure changes in metal toxicity following irradiation. DOC concentrations declined only 20% with UVB irradiation in both samples, although DOC concentration was much higher in the brown‐water sample than in the clear‐water sample. In the brown‐water sample metal toxicity increased up to 78% after 10 days of UVB irradiation for Cu, Zn, Co and Pb, but not for Ni and Cd. Changes were less evident in the clear‐water sample. The differences observed between IC50 values for relatively fresh, high‐DOC water from the headwaters of the Raisin River and much “older,” low‐DOC water from Lake Simcoe point to the likelihood of the effects observed in this study being many times greater in the natural environment because of very long exposure to solar radiation. Alteration of DOC by UVB irradiation may influence primary productivity and species composition, especially in waters in which metal concentrations are high. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 267–274, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10057
Validation of the AeroDyn subroutines using NREL unsteady aerodynamics experiment data
Authors: Laino David J. , Hansen A. Craig , Minnema Jeff E.
Published: October 2002

Completion of the full‐scale wind tunnel tests of the NREL Unsteady Aerodynamics Experiment (UAE) phase VI allowed validation of the AeroDyn wind turbine aerodynamics software to commence. Detailed knowledge of the inflow to the UAE was the bane of prior attempts to accomplish any in‐depth validation in the past. The wind tunnel tests permitted unprecedented control and measurement of inflow to the UAE rotor. The data collected from these UAE tests are currently under investigation as part of an effort to better understand wind turbine rotor aerodynamics in order to improve aeroelastic modelling techniques. Preliminary results from this study using the AeroDyn subroutines are presented, pointing to several avenues towards improvement. Test data indicate that rotational effects cause more static stall delay over a larger portion of the blades than predicted by current methods. Despite the relatively stiff properties of the UAE, vibration modes appear to influence the aerodynamic forces and system loads. AeroDyn adequately predicts dynamic stall hysteresis loops when appropriate steady, 2D aerofoil tables are used. Problems encountered include uncertainties in converting measured inflow angle to angle of attack for the UAE phase VI. Future work is proposed to address this angle‐of‐attack problem and to analyse a slightly more complex dynamics model that incorporates some of the structural vibration modes evident in the test data. Copyright © 2002 John Wiley & Sons, Ltd.
Expanding wake induction effects on thrust distribution on a rotor disc
Authors: Chaney K. , Eggers A. J.
Published: October 2002

Wake expansion is necessary to satisfy conservation of mass when induction in flow through a wind turbine rotor disc is substantial. An iterative model is developed to calculate this expansion in an axisymmetric wake generated by an idealized unyawed disc operating at high tip speed ratios. The model satisfies all conservation constraints and boundary conditions and predicts induction in the wake flow normal to the rotor disc plane due to the sheet of vorticity convected downwind along the surface of the wake. Expansion effects on induction in flow through the rotor disc and in the wake are noted. The effect of skewing the axis of the wake out of alignment with the axis of a yawed rotor disc is approximated with a simple crossflow model which yields an expanding skewed wake. The sheet of vorticity convected downwind along the surface of this wake is found to significantly alter the induction in flow through the rotor disc from that predicted when wake expansion is neglected with the cylindrical wake approximation. This alteration is in the direction of levelizing the induction and resulting thrust distributions on the yawed disc. This in turn reduces the forward shift of the centre of thrust from the axis of a yawed rotor, and this reduction may be very substantial at higher levels of induction and hence wake expansion. The effects of wake expansion on the level of thrust appear to be of second order compared with the effects on centre of thrust. These findings are likely to be of particular importance to small wind turbines which are designed to yaw out of the wind as required at higher wind speeds to prevent undesirable overshoots in power and loads. Copyright © 2002 John Wiley & Sons, Ltd.
Time dependence characterization of Pb and Br concentrations in samples from ombrotrophic peat bogs in Austria and Poland by energy‐dispersive x‐ray fluorescence spectrometry
Authors: Hołyńska B. , Ostachowicz J. , Samek L. , Streli C. , Wachniew P. , Wobrauschek P.
Published: October 2002

It long has been known that ombrotrophic peat bog preserves the record of the atmospheric deposition of metal pollutants. In this paper, the results of an investigation of two peat cores taken in Austria from Langmoos bog located near a motorway and one taken in southern Poland located far away from main roads are presented. The concentration levels of Pb and Br in dated peat cores were studied in order to find out whether the close location of a motorway to a bog will influence the contents of these elements in peat. Copyright © 2002 John Wiley & Sons, Ltd.
Angular dependence of L x‐ray production cross‐section in seven elements from Au to U at 59.5 keV photon energy
Authors: Seven Sabriye , Koçak Kadir
Published: October 2002

The Ll, Lα, Lβ and Lγ x‐ray production cross‐sections in U, Th, Bi, Pb, Tl, Hg and Au were measured using 59.5 keV incident photon energies in the angular range 40–130°. The measurements were performed using the 241Am radioisotope as photon source and a detection system with an Si(Li) detector. Although differential cross‐sections for Lβ and Lγ x‐rays were found to be angle independent, within experimental error, those for Ll and Lα x‐rays were found to be angle dependent. This confirms the angular dependence of measured photon induced Ll and Lα x‐ray production cross‐sections as reported by two groups. Further, the present results also confirm the theoretical predictions of two other groups but are contrary to the results reported by others. Integral cross‐sections for production of Ll, Lα, Lβ and Lγ x‐rays were also deduced and were found to be in good agreement with the theoretical values. Copyright © 2002 John Wiley & Sons, Ltd.
The long‐term sustainability of after‐school programs: The After‐School Corporation's strategy
Authors: Friedman Lucy N. , Bleiberg Mary S.
Published: October 2002

The challenges that The After‐School Corporation has faced in building and sustaining quality after‐school programs that are accessible to every public school student in New York are discussed.
Schools alone are not enough: After‐school programs and education reform in Boston
Authors: Davis Jennifer , Farbman David A.
Published: October 2002

Boston's efforts to expand after‐school programs and build their capacity to support the standards‐based education reforms of the city's public schools are explored.
Ensuring quality and sustainability in after‐school programs
Authors: Chung An‐Me , de Kanter Adriana A. , Stonehill Robert M.
Published: October 2002

The Charles Stewart Mott Foundation and the U.S. Department of Education are engaged in a unique public‐private partnership that strives to integrate the assets and flexibility of philanthropy with the breadth of a major federal program to support meaningful after‐school programs and school‐community partnerships for children, youth, families, and communities.
Reproductive endocrine responses to photoperiod and exogenous gonadotropins in the pallas' cat (Otocolobus manul)
Authors: Brown Janine L. , Graham Laura H. , Wu Julie M. , Collins Darin , Swanson William F.
Published: October 2002

Fecal samples were collected for 14–26 months from three male and six female Pallas' cats (Otocolobus manul) to examine gonadal steroidogenic activity in response to changes in photoperiod and treatment with exogenous gonadotropins. Females exhibited a seasonal anestrus from May–December, excreting consistently low concentrations of fecal estrogens (overall mean, 50.2±8.5 ng/g). During the breeding season (January–April), baseline fecal estrogen concentrations were higher, averaging 128.4±18.9 ng/g, with peak concentrations ranging from 455.8–909.6 ng/g. Interpeak intervals in estrogen excretion ranged between 7 and 21 days, with an average estrous cycle length of 14.3±1.7 days. Two females became pregnant after natural mating, with overall luteal progestogen concentrations averaging ∼40 μg/g throughout gestation. Fecal estrogens increased in mid‐gestation, peaking just before birth. Induction of follicular development with eCG (100–300 IU, i.m.) resulted in an increase in fecal estrogens (peak range, 263.1–1198.1 ng/g), followed by a postovulatory increase in fecal progestogens (overall mean, 41.1±11.9 μg/g) after hCG (75–150 IU, i.m.). Despite apparently normal ovarian responses, none of the females conceived after artificial insemination (AI). The gonadotropin‐induced nonpregnant luteal phase lasted 49.8±5.3 days (range, 30–60 days), whereas gestation lasted ∼70 days. In the male Pallas' cat, fecal androgens were elevated from November–April (overall mean, 352.3±30.3 ng/g) compared with nadir concentrations during the rest of the year (82.1±3.3 ng/g). Entrainment of seasonality to photoperiod was demonstrated by stimulation of gonadal steroidogenic activity in cats exposed to increasing artificial light during natural (nonbreeding season) and artificially induced short‐day photoperiods. In summary, reproduction in Pallas' cats is highly seasonal and photoperiod‐dependent. Females exhibit elevated baseline and peak fecal estrogen concentrations for 3–4 months during late winter/early spring. Testicular steroidogenic activity precedes the rise in female estrogen excretion by about 2 months, presumably to ensure maximal sperm production during the breeding season. Zoo Biol 21:347–364, 2002. Published 2002 Wiley‐Liss, Inc.
Veterinary concerns of captive duikers
Authors: Willette Michelle M. , Norton Terry L. , Miller Christine L. , Lamm Marnie G.
Published: October 2002

In March 2000, professionals from various duiker‐holding institutions conducted a workshop at the Wildlife Conservation Society’s Wildlife Survival Center (WCS/WSC) on St. Catherine’s Island entitled Husbandry, Nutrition, and Health of Captive Duikers. The product of this workshop was a suite of monographs, one of which dealt with veterinary issues and took the form of a series of veterinary guidelines. These guidelines are based on the general disease and management concerns of neonatal and adult duikers, and include: 1) preventive medicine recommendations with preshipment, quarantine, and routine physical examination protocols; 2) restraint and anesthesia recommendations; 3) a necropsy protocol; and 4) a summary of medical informational needs. The main intent of these protocols is to outline minimum standards of veterinary care and inquiry for duiker species in captivity. Eventually, this will result in the establishment of a consistent and comprehensive data base, from which future individuals will greatly benefit in the form of improved husbandry, nutrition, and medicine. Zoo Biol 21:197–207, 2002. © 2002 Wiley‐Liss, Inc.
Rayleigh‐Bénard convection as a tool for studying dust devils
Authors: Fiedler Brian H. , Kanak Katharine M.
Published: October 2002

Intense columnar vortices in a convecting layer are explored with direct numerical simulations that are otherwise similar to the large‐eddy simulations of6, Q. J. R. Meteorol. Soc. 126, 2789–2810). With free‐slip boundaries and a Rayleigh number of 106(4096 times critical), vortices similar to large dust devils are readily produced. The genesis, intensity and life cycle of these intense vortices (dust devils) are studied. The simulated dust devils last for the order of the over‐turning time of the largest eddies. The intensity is limited by the hydrostatic pressure drop supported by the buoyancy confined in the core. The genesis of a simulated dust devil requires not only tilting of the baroclinically generated vorticity, but also a symmetry‐breaking event that allows one sign of vorticity to become concentrated in an updraft. Such symmetry breaking is the rule with random initialization in the simulations. However, when initialization is restricted to certain Fourier modes, exceptions are found that produce only symmetric vortex couplets that are relatively weak. Copyright © 2001 Royal Meteorological Society.
Failure of sister chromatid separation leads to formation of diplochromosomes in colcemid treated PtK1 cells
Authors: Ghosh Sibdas , Paweletz Neidhard , Schroeter Dieter
Published: October 2002

The origin of diplochromosomes has been traced in multinucleate rat kangaroo cells (PtK1) obtained after colcemid treatment. In these cells the diplochromosomes were shown to originate from restitution nuclei, indicating that they were formed due to the omission or failure of sister chromatid separation and not due to endoreduplication. In this context the mechanism of sister chromatid separation has been discussed. The independence of this mitotic event from other associated processes, such as chromosome condensation, nuclear envelope breakdown or spindle formation has been stressed.
Disruption of microtubules induces formation of actin fibrils in density‐inhibited 3T3 cells.
Authors: Kajstura J. , Bereiter‐Hahn J.
Published: October 2002

In density‐inhibited 3T3 fibroblast cultures F‐actin is localized almost exclusively at the cell‐to‐cell borders. Depolymerization of microtubules results in a rearrangement of the F‐actin pattern. Numerous actin bundles are formed, most of them are anchored to the cell borders. This rearrangement is preceded by a transient rise in F‐actin content.
The absence of confronting cisternae following thymidine‐induced synchronization in HeLa cells
Authors: Palisano John R.
Published: October 2002

This is the first report of the elimination of confronting cisternae (CC), prominent organelles in dividing HeLa cells, upon experimental manipulation of the cells. CC are lost when a double thymidine block is employed to synchronize cell division. This observation is consistent with the hypothesis that the occurrence of CC in some fetal cells and in selected tumor cells depends on the speed at which the cells cycle through mitosis. If thymidine blocks DNA synthesis and arrests cells at the G1/S interface, then thymidine probably has an indirect effect on CC. This paper reports the effect of thymidine on the occurrence of CC and briefly discusses how inhibitors of membrane synthesis or microtubule polymerization may affect the occurrence of CC during mitosis.
Insulin rescues the unicellular eukaryote Tetrahymena from dying in a complete, synthetic nutrient medium
Authors: Christensen Søren T.
Published: October 2002

The presence of 10−6 M bovine insulin in chemically defined nutrient medium prevented cell death and improved cell proliferation of the ciliate Tetrahymena pyriformis when inoculated at low initial cell density. The action of insulin was found to be restricted to the 22‐30 fragment of the B‐chain. These results suggest that small peptides are involved in regulation of cell survival and cell proliferation in Tetrahymena pyriformis.
Matrix metalloproteinases and endometrial remodelling.
Authors: Salamonsen Lois A.
Published: October 2002

Menstruation, angiogenesis, embryo implantation and placentation are natural processes involving degradation of the extracellular matrix within the endometrium. A number of matrix metalloproteinases (MMPs) and their natural tissue inhibitors (TIMPs) have now been identified in association with these processes. In particular, mRNA for proMMP‐1 and proMMP‐3 and for TIMP‐1 and TIMP‐2 are elevated in human endometrial tissue at menstruation compared with other times of the female reproductive cycle. ProMMPs −1, −2, −3 and −9 are released from cultured human endometrial stromal cells, production of all but proMMP‐2 being regulated by cytokines known to be expressed in human endometrial epithelium. At least two gelatinases are released by ovine trophoblast in culture and can be flushed from the uterine lumen at the time of implantation. Thus, matrix metalloproteinases clearly have roles in normal endometrial functions.
Hormones and neurotransmitters release: four mechanisms of secretion
Authors: Dunant Yves
Published: October 2002

Distinct mechanisms operate in different secreting systems, they are 1) free diffusion through the plasma membrane; 2) exocytosis resulting from fusion of a secretory granule with the plasma membrane; 3) fleeting release from a granule through a transient pore without full fusion; 4) release through a specialised plasmalemmal molecule such as the mediatophore. The latter mechanism is proposed to operate in rapid synapses in which the neurotransmitter is emitted as an abrupt chemical impulse of quantal composition. There, release is momentarily signalled in the plasma membrane by large intramembrane particles. Synaptic vesicles are also essential for regulation of this type of release. They fuse with the plasma membrane only late after activity and seem to be involved in calcium sequestration and extrusion.
Benzamide‐induced changes in the actin cytoskeleton in human skin fibroblasts.
Authors: Korohoda W. , Michalik M. , Pierzchalska M.
Published: October 2002

The incubation of human skin fibroblasts in the presence of 10 mM benzamide in Joklik's modification of Eagle's Minimal Essential Medium caused an extensive reorganization of actin filaments. The disappearance of stress fibers and changes in cell morphology were observed, whereas no changes in the microtubule architecture were noticed. The observed effects appeared fully reversible within 3 hours after the removal of benzamide. The results are discussed in relation to the two known activities of benzamide as an anaesthetic and an inhibitor of ADP‐ribosylation.
A high phosphotyrosine phosphatase activity is present in differentiating bovine lens cells
Authors: Blanquet Pierre R. , Croquet Frederic
Published: October 2002

Activity of phosphotyrosine ‐ protein phosphatases (PTPases) has been investigated in the different cellular regions of bovine eye lens. PTPases were tested in cellular detergent extracts using phospholabelled synthetic peptides and p‐nitrophenyl phosphate. We show that a high PTPase activity is only present in cells which undergo differentiation, namely the equatorial epithelium and cortex fiber cells. Since this activity is found to be severely inhibited by a specific inhibitor of receptor ‐ type PTPases, it can be suggested that one or more members of this class of PTPases might play an important role in the lens differentiation process.
Glycolipid patterns during xenopus embryo development
Authors: Gornati Rosalba , Rizzo Angela M. , Tong Xiao‐Wei , Berra Bruno , Bernardini Giovanni
Published: October 2002

Glycolipid patterns have been studied during the first six days of Xenopus embryo development. Glycolipid contents showed a sharp increase more evident after the third day of development. Glucosylceramide and sulphatide are not only the most represented species, but also those which exhibit a statistically significant percentage change during early development. Among gangliosides, GD3 is the most represented specie. Two polysialylated gangliosides with not yet established structures are also present.
MUSCARINIC ACETYLCHOLINE RECEPTOR SUBTYPE mRNAs IN THE HUMAN AND RAT VESTIBULAR PERIPHERY
Authors: WACKYM PHILLIP A. , CHEN CAROLINE T. , ISHIYAMA AKIRA , PETTIS ROBERT M. , LÓPEZ IVÁN A. , HOFFMAN LARRY
Published: October 2002

The expression of the five muscarinic acetylcholine receptor (mAChR) subtypes (m1–m5) in the vestibular end‐organs and in the primary afferent vestibular ganglia of the human and rat was studied using RT‐PCR from the two tissue populations from both species. In the human, although all five mAChR subtypes were expressed in brain, only the m1, m2, and m5 mAChR subtypes were amplified from both the vestibular ganglia and the vestibular end‐organs, while in the rat, all five mAChR subtypes were expressed. These data suggest that the efferent cholinergic axo‐dendritic and axo‐somatic synapses have a muscarinic component and that there are pharmacologic implications for patients with vestibular dysfunction.
THE EXPRESSION OF ESTROGEN RECEPTOR AND ESTROGEN EFFECT IN MBA‐15 MARROW STROMAL OSTEOBLASTS
Authors: SHAMAY A. , KNOPOV V. , BENAYAHU D.
Published: October 2002

MBA‐15, a marrow stromal‐derived cell line, was shown to express an estrogen receptor. This finding was confirmed byin situhybridization and receptor binding assay. An exposure to estrogen (10−12–10−6m) in a dose response manner resulted in a decrease of cell proliferation as measured by MTT assay. Cell function was measured by enzymatic activities of two osteoblastic markers, CD10/NEP and alkaline phosphatase. These enzymatic activities were elevated following the estrogen treatment. This model enabled direct evaluation of the estrogen effect on stromal osteoblast cells.
MONOCLONAL ANTIBODY RAISED AGAINST HUMAN MITOTIC CYCLIN B1IDENTIFIES CYCLIN B‐LIKE MITOTIC PROTEINS IN SYNCHRONIZED ONION (ALLIUM CEPA L.) ROOT MERISTEM
Authors: CHAUDHURI SADHAN K. , GHOSH SIBDAS
Published: October 2002

Cyclin B‐like mitotic proteins have been detected in synchronized Allium cepa L. root tip cells by using mouse monoclonal anti‐cyclin B1antibody raised against human cyclin B1Immunoblot shows two closely placed isoforms of cyclin B‐like proteins having an apparent molecular weight around 54 kDa. In vivo [35S]‐methionine labelling followed by immunoprecipitation and autoradiography indicates that cyclin B‐like proteins are mainly synthesized in the G2 phase of the cell cycle and destroyed in late mitosis. Immunoblotting data depict that the level of cyclin B‐like proteins reaches the maximum at the late G2 to early M phase; and it becomes degraded in the late hours of mitosis. Moreover, the cyclin B isoforms are stabilized in colchicine‐arrested metaphase cells as already reported in animal cells.
NUCLEAR FACTOR OF ACTIVATED T CELLS (NFAT) IS A POSSIBLE TARGET FOR DEXAMETHASONE IN THYMOCYTE APOPTOSIS
Authors: WISNIEWSKA MARTA , STANCZYK MAGDALENA , GRZELAKOWSKA‐SZTABERT BARBARA , KAMINSKA BOZENA
Published: October 2002

Cell death plays a critical role in the generation of an effective immune system. During maturation T lymphocytes are generated, censored and eliminated in the thymus. These events are temporally associated with developmental changes in the levels of transcription factors including NFAT. The NFAT transcription factor (nuclear factor of activated T cells) is implicated in the regulation of T‐lymphocyte proliferation and transcriptional activation of genes encoding lymphokines. It has been demonstrated that discontinuities in the inducibility of NFAT and AP‐1 transcription factors occur during transition of immature thymocytes into cortical thymocytes which are eliminated by apoptosis.

To understand the molecular basis of these developmental intrathymic changes, we studied DNA‐binding activities of transcription factors during dexamethasone‐induced apoptosis of immature thymocytes. We observed a specific loss of NFAT DNA‐binding activity after dexamethasone treatment. It correlated with a selective disappearance of one out of two AP‐1 complexes. Our data suggest that NFAT complex is a possible target in dexamethasone‐induced apoptosis.
CELL SURFACE LOCALIZATION OF THE 60 kDa HEAT SHOCK CHAPERONIN PROTEIN (hsp60) IN MAMMALIAN CELLS
Authors: SOLTYS BOHDAN J. , GUPTA RADHEY S.
Published: October 2002

To investigate whether the 60‐kDa heat shock chaperonin protein (hsp60) is present on the surface of mammalian cells, we used immunogold labeling of intact cells and backscattered electron imaging to image gold particles. Chinese hamster ovary cells and the human leukemic CD4‐positive T‐cell line CEM‐SS on glass coverslips were labeled using affinity‐purified monoclonal and polyclonal antibodies specific for hsp60 and 30 nm gold markers. Cells were imaged using the scanning mode of the conventional transmission electron microscope. Backscattered electron imaging provided definitive identification of the gold markers while secondary electron imaging gave information on surface architecture. Labeling intensity was 250–800 gold particles per cell in Chinese hamster ovary cells and 600–2000 in CEM‐SS human lymphoblasts. The finding of hsp60 on the cell surface of mammalian cells may signify chaperone involvement in surface functions.
COMPARISON OF THE EFFECT OF DIFFERENT SHORT CHAIN FATTY ACIDS ON THE GROWTH AND DIFFERENTIATION OF HUMAN COLONIC CARCINOMA CELL LINESIN VITRO
Authors: SIAVOSHIAN SAMILA , BLOTTIÈRE HERVÉ M , LE FOLL ERIC , KAEFFER BERTRAND , CHERBUT CHRISTINE , GALMICHE JEAN‐PAUL
Published: October 2002

The aim of this study was to compare the effects of acetate, propionate, butyrate, iso‐butyrate, valerate, iso‐valerate and caproate on cell growth and on the activities of alkaline phosphatase (AP) and dipeptidyl aminopeptidase IV (DPP IV) by three human colonic adenocarcinoma cell lines. In addition to butyrate, propionate and valerate inhibited cell proliferation of the three cell lines. The other SCFAs did not influence cell proliferation. AP and DPP IV activities were strongly stimulated by butyrate on two of the three cell lines. On HT‐29, AP was strongly stimulated, however DPPIV expression remained undetectable. Propionate and valerate exhibited a weaker stimulation, the other SCFAs being ineffective. The effect of SCFAs on cell proliferation and differentiation clearly depends on the number of carbons and on the configuration of the basic structure of the molecule.
DECREASE IN P53 PROTEIN IN CULTURED CARDINAL LIGAMENT FIBROBLASTS FROM PATIENTS WITH PROLAPSUS UTERI
Authors: YAMAMOTO MARI , AOYAGI MASARU , AKAZAWA KENJI , TAJIMA SHINGO , YAMAMOTO KIYOTAKA
Published: October 2002

The authors examined the growth response of cardinal ligamental fibroblasts derived from patients with prolapsus uteri (HPLiF) and compared it with the response of those from control subjects (HCLiF). The growth rate during the logarithmic growth phase was not different between HPLiF and HCLiF, while the cell density at confluence (saturation density) was significantly higher in HPLiF than in HCLiF. When added alone, platelet‐derived growth factor (PDGF), insulin‐like growth factor‐I (IGF‐I), and epidermal growth factor (EGF) produced minimal effects on DNA synthesis in HCLiF. The simultaneous addition of PDGF, IGF‐I and EGF synergistically stimulated the DNA synthesis. In contrast, PDGF alone was able to initiate DNA synthesis in HPLiF. The combination of PDGF, IGF‐I, and EGF significantly stimulated the DNA synthesis of HPLiF compared with HCLiF. p53 protein and p53 gene transcripts decreased by 50% in HPLiF. The anti‐WAF1 antibody reacted intensely with a 21‐kDa protein in the homogenates of control fibroblasts, while the immunoreactive band in prolapsus fibroblasts was clearly reduced. These results indicate that the higher proliferative activity at near confluency in prolapsus fibroblasts may result from the decreased expression of p53 protein and p53 mRNA followed by the decrease in p21 protein. Furthermore, the failure of cells to enter quiescence may lead to a decrease in the synthesis and deposition of elastin and thus may contribute to the loss of supportive function in uterine connective tissues.
APOPTOSIS, REDIFFERENTIATION AND ARRESTING PROLIFERATION SIMULTANEOUSLY TRIGGERED BY OXIDATIVE STRESS IN HUMAN HEPATOMA CELLS
Authors: REN JIAN‐GUO , ZHENG RONG‐LIANG , SHI YI‐MING , GONG BO , LI JIAN‐FENG
Published: October 2002

The effects of oxidative stress (ascorbic acid—ferrous system) on the proliferation, differentiation and apoptosis of the human hepatoma cell SMMC‐7721 were studied. Oxidative stress significantly inhibited cell proliferation and induced morphological differentiation. Whatever the indices related with cell malignancy, such as α‐fetoprotein and c‐glutamyltranspeptidase or the index related with cell differentiation, such as tyrosine‐α‐ketoglutarate transaminase, all inclined evidently to normalization. The tumour's clonogenic potential decreased significantly. Moreover, together with differentiation, the phenomenon of apoptosis was found by the appearance of apoptotic bodies, detached cells, and apoptotic morphological feature. Although, their DNA was not degraded into oligonucleosomal fragmentation, the DNA was cut into larger fragments (about 21.2kbp) of a size associated with chromatin loops. These findings indicated that oxidative stress can induce both differentiation and apoptosis simultaneously in tumour cells. All the results showed that oxidative stress may initiate the tumour cells reverse transformation. The possible mechanism of the differentiation and apoptosis induced by oxidative stress may be related to the lipid peroxidation of cell membrane.
THE ROLE OF Ca IONS IN RESTORATION OF THE STRUCTURE OF INTERPHASE AND MITOTIC CHROMOSOMES IN PK LIVING CELLS AFTER HYPOTONIC STRESS
Authors: AMCHENKOVA A. A. , BUZHURINA I. M. , GORGIDZE L. A. , KIREYEV I. V. , PANOV M. A. , POLYAKOV V. JU.
Published: October 2002

The dynamics of mitotic chromosome and interphase chromatin recondensation in living PK cells during their adaptation to hypotonic medium was studied. The recondensation process was found to be slowed down by the modification of plasma membrane with low concentrations of glutaraldehyde, while osmotic reactions of glutaraldehyde‐treated cells remain unchanged. The effect of glutaraldehyde can be rapidly reversed by the addition of Ca2+‐ionophore A23187. Intracellular Ca2+measurements show that the adaptation to hypotonic shock is accompanied by restoration of free Ca concentration, whereas the delay of chromatin condensation in glutaraldehyde‐treated cells is paralleled by the decrease of Ca level. The mechanisms implying the role of low concentration of Ca2+in chromatin compactization in vivo are discussed.
EXPRESSION OF THE CELL ADHESION MOLECULE E‐CADHERIN BY THE HUMAN BONE MARROW STROMAL CELLS AND ITS PROBABLE ROLE IN CD34+STEM CELL ADHESION
Authors: Turel K. R. , Rao S. G. A.
Published: October 2002

Bone marrow stroma is the physical basis of the haematopoietic microenvironment and regulates several key features of stem cell proliferation and differentiation. It plays a crucial role in maintaining haematopoietic homeostasis. Earlier studies have shown that this is achieved through interactions with the extracellular matrix and specific molecules called the cell adhesion molecules (CAMs). In this paper, we show that E‐cadherin, a cell adhesion molecule which plays a crucial role in cell—cell aggregation during development, is also present in the bone marrow stroma. The expression of the CAM can also be demonstrated on a subset of CD34+stem cells. Stromal expression of E‐cadherin is decreased when treated with lymphokine mixture, phytohaemagglutinin‐treated‐leukocyte‐conditioned medium (PHA‐LCM). This is the reverse of ICAM‐I expression, which increases with PHA‐LCM treatment. E‐cadherin shows homotypic and homophilic interaction and its presence on a subset of CD34+cells leads to speculation on whether this CAM has a role in adherence of primitive stem cells to the marrow stroma.
PROTEIN KINASE C AFFECTS REFORMATION OF ENDOTHELIAL JUNCTIONS IN XENOPUS XTH‐2 CELLS
Authors: Werner Nicole Susann , Meyer Rainer , Achenbach Friedhelm
Published: October 2002

Endothelial cells can reversibly be forced to suppress the formation of endothelial junctions (EJ) by cultivation in a low calcium medium. The authors localized vinculin and cadherin as marker proteins of EJ and actin as a cytoskeletal component by fluorescence microscopy, and used this cell model to study the reformation of endothelial junctions under conditions of activation and inhibition of protein kinase C (PKC). Inhibition of PKC by H‐7 leads to an acceleration of EJ reformation, while constitutive activation by TPA inhibits the reformation process.
LOVASTATIN INDUCES MITOTIC ABNORMALITIES IN VARIOUS CELL LINES
Authors: Lamprecht Jan , Wójcik Cezary , Jakóbisiak Marek , Stoehr Micheal , Schrorter Dieter , Paweletz Neidhard
Published: October 2002

We examined the effects of lovastatin, a common anti‐atherosclerotic drug and a blocker of the cell cycle, on the process of mitosis. It is known that lovastatin induces an arrest or a retardation of the cell cycle in many cell types not only at the G1phase, but also at the G2/M transition. After 24–48h incubation of epithelial PtK2, T24, HeLa cells and fibroblastic L929 cells in the presence of 1.0–60.0μm lovastatin, diverse mitotic perturbations have been observed. The most noteworthy phenomena recorded were prometaphase retardation and chromosome lagging during metaphase and anaphase. After the recovery in lovastatin‐free media, the cells continued mitosis without any disturbances. Mevalonic acid prevented the effects of lovastatin. We conclude that the effects were specific for lovastatin‐induced inhibition of mevalonic acid synthesis. Immunofluorescence studies with anticentromeric antibodies suggested that one of the possible causes of the lovastatin‐induced mitotic disorder could be an interference with the development and function of the centromeres.
PURIFICATION AND CHARACTERIZATION OF A NOVEL 35‐kDa PROTEIN FROM TRANSFORMED CARDIOMYOCYTES
Authors: Chandrasekhar Sundararaman , Münster Pamela N. , Henzel William A. , Daud Adil I.
Published: October 2002

A 35‐kDa protein (designated p35) showing antigenic homology with an N‐terminal epitope on the SV‐40 large T‐antigen oncoprotein was purified from transformed cardiomyocytes. Sequence analysis of several tryptic peptides indicated that p35 was not homologous to previously described sequences. Polyclonal antibody raised against synthetic peptide containing one of the tryptic fragments was used in Western blot analyses to ascertain the tissue‐specific pattern of p35 expression. p35 was expressed ubiquitously in adult mouse tissues, and was detected in both embryonic and transformed cardiomyocyte preparations. Subcellular fractionation studies indicated that p35 is an integral membrane protein. Expression of p35 appeared to be regulated by growth conditions as evidenced by a transient decrease in protein levels following the addition of serum to quiescent NIH 3T3 cells.
A MOUSE FIBROBLAST LINE CYCLES BETWEEN MONOLAYER AND SPHEROID FORMS, REGULATES MET AND HGF EXPRESSION, AND RELEASES AN ATTACHMENT AND GROWTH‐PROMOTING SUBSTANCE
Authors: Halverson Douglas O. , Resau James , Faletto Donna , Fisher Robert , Anver Miriam , Rong Sing , May Jo Ann , Tsarfaty Ilan , Blair Donald G.
Published: October 2002

A subline of mesoderm‐derived mouse NIH3T3 fibroblasts was selected for its ability to proliferate in serum‐free media. This cell line (SFDH) grows as a monolayer at low density and spontaneously forms dense, multicellular spheroids at high density. Spheroid formation can also be induced by the addition of dexamethasone, polybrene, or heparin. Spheroids eventually detach from the substrate, but will reattach and re‐form monolayers when transferred to fresh culture vessels and media, repeating the cycle again upon reaching high density. Thin section analysis of spheroids shows morphologically‐distinct regions of cells, including an attenuated outer surface and a cuboidal interior with occasional lumen‐like areas. Over time in culture, spheroids express increasing levels of met, the Met ligand‐SF/HGF and cytokeratin, an epithelial marker, in comparison to monolayers. Both monolayer and spheroid‐derived cells are rapidly tumorigenic in nude mice. Media conditioned by SFDH cells contain factors that stimulate growth and attachment of a variety of tumorigenic and non‐tumorigenic cell lines, inducing cells to divide in serum‐free media for up to 14 days when plated on tissue culture‐treated and nontreated plastic surfaces pre‐coated with SFDH conditional media. The growth‐stimulating activity fractionates as a single peak over a sepharose column in the presence of 6m urea, and sediments as a high molecular weight complex. Growth‐stimulating activity can be neutralized by several antisera specific for hepatocyte growth factor, and the same sera recognize a novel ∼37kD protein in active supernatants. The cyclic, continuous nature of alternating monolayer and spheroid forms makes this cell line appropriate for studying changing gene expression patterns in progressive cell—cell/cell—matrix interactions.
DOES THE BCR/ABL‐MEDIATED INCREASE IN THE EFFICACY OF DNA REPAIR PLAY A ROLE IN THE DRUG RESISTANCE OF CANCER CELLS?
Authors: Majsterek Ireneusz , Blasiak Janusz , Mlynarski Wojciech , Hoser Grazyna , Skórski Tomasz
Published: October 2002

BCR/ABL oncogenic tyrosine kinase is responsible for the pathogenesis of Philadelphia chromosome‐positive human leukemia and is generated by a specific reciprocal chromosome translocation, t(9;22)(q34−;q11+). We examined the role of DNA repair in therapeutic drug resistance to idarubicin in the murine pro‐B lymphoid cell line BaF3 and its BCR/ABL ‐transformed clone. These cells can be used as models of human leukemias. The MTT assay revealed that BCR/ABL ‐transformed cells displayed resistance to idarubicin in the range 0.3–0.5μm, compared with the control BaF3 cells. Idarubicin at 0.3 and 1μm induced DNA damage in the form of strand‐breaks and/or alkali labile sites in both transformed and control cells in comet assays. TheBCR/ABL ‐transformed cells needed only 60min to remove damage to their DNA, whereas controls took 120min. We hypothesize that this observed increase in the efficacy of repair in BCR/ABL‐ positive cells is involved in their resistance to idarubicin.
UPTAKE OF CADMIUM IONS IN WHITE‐ROT FUNGUS TRAMETES VERSICOLOR: EFFECT OF CD (II) IONS ON THE ACTIVITY OF LACCASE
Authors: Jarosz‐Wilkołazka Anna , Malarczyk Elzbieta , Pirszel Jacek , Skowroński Tadeusz , Leonowicz Andrzej
Published: October 2002

The effects of cadmium Cd (II) ions on the physiology and biological activity of Trametes versicolor, a strain belonging to white‐rotting Basidiomycetes, were examined. Cd (II) ions were added to 10‐day‐old cultures grown on a liquid medium, or at the time of inoculation. Our experiments showed that T. versicolor is a good cadmium biosorbent from aqueous solution, this strain removing almost all the Cd (ll) ions over the first 2h of incubation by what appears to be a rapid, energy‐independent surface binding phenomenon, at the rate of ∼2mg Cd per g mycelial dry weight. An additional slower and energy‐dependent transport mechanism was also present, taking in ∼0.3mg Cd (II) perg dry weight. It is also shown that these Cd (II) ions significantly stimulate the activity of extracellular laccase when added to 10‐day‐old cultures.
Key to the Genera of the Lichinaceae
Authors: Schultaz Matthias , Büdel Burkhard
Published: October 2002

A key is provided to all genera currently included in the cyanobacterial lichen family Lichinaceae as well as some close relatives. Characteristic features of the family are described and illustrated.
Heightened North Pacific Storminess during Synchronous Late Holocene Erosion of Northwest Alaska Beach Ridges
Authors: Mason Owen K. , Jordan James W.
Published: October 2002

A progradational regime of falling sea level and/or high sediment input has produced extensive beach ridge plains in northwest Alaska during the last 4000 yr. Eleven Chukchi Sea beach ridge complexes, oriented at various angles to wind fetch, provide a cumulative history of longshore transport and erosion. Archaeological and geological upper limiting radiocarbon ages (n = 59) allow correlations between depositional units on seven beach ridge complexes. Progradation started 4000 yr B.P. at nearly all complexes, as eustatic sea level stabilized. Two disconformities or truncations are found on most of the complexes, providing time-parallel storm horizons, dated at 3300-1700 and 1200-900 14C yr B.P. Between 1700 and 1200 14C yr B.P. most of the complexes prograded, indicating the predominance of less-stormy conditions. Modern synoptic patterns that produce Chukchi beach ridge erosion are linked to northerly shifts in North Pacific storm tracks. The regionwide beach ridge erosional truncations correlate with records of glacier expansion, heightened precipitation evident in tree-rings, stream flooding, and shelf deposits reworked by storm surges.
A Preliminary Report of Changing Quaternary Mammal Faunas in Subalpine New Guinea
Authors: Hope Geoffrey , Flannery Tim , Boeardi
Published: October 2002

The faunas found in the mountains of central Irian Jaya have experienced dramatic changes through the late Quaternary. Remains of two previously unknown species of large marsupial,Maokopia ronaldiandProtemnodon hopei,have been recovered from unrelated cave and fluvial deposits which today occur in dense upper montane forest. Direct dating of the finds has not as yet been possible, but stratigraphic, sedimentologic, and palynologic evidence indicates that these species lived near a climatic treeline in subalpine grassland in the late Pleistocene. At higher altitudes a rockshelter provided the second known mid-Holocene record ofThylogale christenseniandThylogale sp. cf. brunii,apparently extinct grassland wallabies. The two largest remaining subalpine mammal species are being locally exterminated by hunting, leaving only a large murid,Mallomys gunung,which weighs less than 2.0 kg. The area thus records the disappearance of a grassland-adapted fauna. The possumPseudocheirops cupreusdominates in modem hunting returns, although this species is totally absent from the local fossil records. It may thus be in the process of invading a vacated and disturbed niche from the upper montane forest.