bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects on toes from prenatal exposure to anticonvulsants
Authors: Bokhari Aquba , Connolly Susan , Coull Brent A. , Harvey Elizabeth A. , Holmes Lewis B.
Published: October 2002

Background

Changes in the distal phalanges of the fingers, including coned epiphyses and hypoplasia of the phalanges, are recognized teratogenic effects of the anticonvulsant drugs phenytoin and phenobarbital. We hypothesized that the frequency of these changes would also be increased in the toes of children exposed to these drugs in comparison to unexposed children.

Methods

We report on the findings in an analysis of radiographs of the feet of 63 children exposed in utero to either phenytoin alone, phenobarbital alone or both drugs and 56 unexposed comparison children.

Results

Only subtle changes were identified. The frequency of coned epiphyses and hypoplasia of phalanges of the toes was the same in both the anticonvulsant and unexposed children. Among the anticonvulsant‐exposed children, however, there was a strong association between the presence of coned epiphyses in the feet and in the hands: all five children with coned epiphyses in the hands, as described previously in the same individuals by Lu et al. ([2000] Teratology 61:277–283) had coned epiphyses in their feet (P = 0.0012). Measurements showed a shortening of metatarsals in all three treatment groups, but this was significant only in the phenytoin monotherapy‐exposed children.

Conclusions

Subtle changes are present in the phalanges and metatarsals of the feet of anticonvulsant‐exposed children, but the overall frequency is much less than occurred in the hands of the same children. We conclude that the presence of either coned epiphyses or hypoplasia of the phalanges of the toes cannot be considered a distinctive feature of the teratogenicity of the anticonvulsant drugs phenytoin and phenobarbital. Teratology 66:122–126, 2002. © 2002 Wiley‐Liss, Inc.
Determining toxicity of leachates from Florida municipal solid waste landfills using a battery‐of‐tests approach
Authors: Ward Marnie L. , Bitton Gabriel , Townsend Timothy , Booth Matthew
Published: October 2002

The toxicity and physicochemical parameters of municipal solid‐waste (MSW) landfill leachates from six sites in north and north‐central Florida, United States, were determined. Landfill leachates are complex mixtures of organic and inorganic constituents. Leachate toxicity was assayed using the acute C. dubia (48‐h) and Microtox™ (15‐min) assays and the chronic S. capricornutum (96‐h) assay. The landfill leachates were shown to be highly toxic to both C. dubia and S. capricornutum with an EC50 < 10% and < 15%, respectively. However, Microtox™ was not as sensitive to the leachates. Based on these results, the assays were ranked for their sensitivities to the landfill leachates; C. dubia > S. capricornutum > Microtox™. Chemical analyses showed high concentrations of un‐ionized ammonia and salts in the landfill leachates but low concentrations of heavy metals. The toxicity of the landfill leachates varied between the sites sampled and within each of the landfill sites. A significant relationship was found between the total ammonia content of the leachates and toxicity as determined by the C. dubia and S. capricornutum assays. Although the chemical constituents in Florida MSW landfill leachates may be more dilute, the toxicity of the leachates is equivalent to that from industrial waste landfills. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 258–266, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10053
The influence of maternal exposure to volatile organic compounds on the cytokine secretion profile of neonatal T cells
Authors: Lehmann I. , Thoelke A. , Rehwagen M. , Rolle‐Kampczyk U. , Schlink U. , Schulz R. , Borte M. , Diez U. , Herbarth O.
Published: October 2002

Indoor VOC (volatile organic compound) exposure has been shown to be correlated with airway symptoms and allergic manifestations in children. An investigation was conducted within an ongoing birth cohort study (LISA: Lifestyle–Immune System–Allergy) of the association between maternal exposure to VOCs and immune status at birth, in particular the cytokine secretion profile of cord‐blood T cells. In a randomly selected group of 85 neonates, cytokine‐producing cord‐blood T cells were analyzed using intracellular cytokine detection. VOC exposure was measured in children's dwellings by passive sampling, while parents were asked to complete questionnaires about possible sources of VOC exposure. Adjusted odds ratios (ORs) were calculated by logistic regression based on categorized quartiles. A positive association was found between elevated percentages of interleukin‐4‐producing (IL‐4) type 2 T cells and exposure to naphthalene (OR = 2.9) and methylcyclopentane (OR = 3.3). Exposure to tetrachloroethylene was associated with reduced percentages of interferon‐γ‐producing (IFN‐γ) type 1 T cells (OR = 2.9). In addition, smoking during pregnancy was correlated with a higher indoor air concentration of naphthalene (OR = 3.8), new carpets in infants' bedrooms with elevated methylcyclopentane concentrations (OR = 4.1), and home renovation with a higher trichloroethylene burden (OR = 4.9). Our data suggest that maternal exposure to VOC may have an influence on the immune status of the newborn child. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 203–210, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10055
Exploiting coherence in hierarchical visibility algorithms
Authors: Bittner Jiří , Havran Vlastimil
Published: October 2002

We present a series of simple improvements that make use of temporal and spatial coherence in the scope of hierarchical visibility algorithms. Thehierarchy updatingavoids visibility tests of certain interior nodes of the hierarchy. Thevisibility propagationalgorithm reuses information about visibility of neighbouring spatial regions. Finally, theconservative hierarchy updatingavoids visibility tests of the hierarchy nodes that are expected to remain visible. We evaluate the presented methods in the context of hierarchical visibility culling usingocclusion trees. Copyright © 2002 John Wiley & Sons, Ltd.
Detached‐eddy simulation of flow around the NREL Phase VI blade
Authors: Johansen J. , Sørensen N. N. , Michelsen J. A. , Schreck S.
Published: October 2002

The detached‐eddy simulation model implemented in the computational fluid dynamics code EllipSys3D is used to calculate the flow around the non‐rotating NREL Phase VI wind turbine blade. Results are presented for flow around a parked blade at fixed angle of attack and a blade pitching along the blade axis. Computed blade characteristics are compared with experimental data from the NREL/NASA Ames Phase VI unsteady experiment. The detached‐eddy simulation model is a method for predicting turbulence in computational fluid dynamics computations, which combines a Reynolds‐averaged Navier–Stokes method in the boundary layer with a large‐eddy simulation in the free shear flow. The present study focuses on static and dynamic stall regions highly relevant for stall‐regulated wind turbines. Computations do predict force coefficients and pressure distributions fairly well. Results using detached‐eddy simulation show considerably more three‐dimensional flow structures compared to conventional two‐equation Reynolds‐averaged Navier–Stokes turbulence models, but no particular improvements are seen in the global blade characteristics. Copyright © 2002 John Wiley & Sons, Ltd.
Navier–Stokes predictions of the NREL phase VI rotor in the NASA Ames 80 ft × 120 ft wind tunnel
Authors: Sørensen N. N. , Michelsen J. A. , Schreck S.
Published: October 2002

This article describes the application of an incompressible Reynolds‐averaged Navier–Stokes solver to several upwind cases from the NREL/NASA Ames wind tunnel tests. In connection with the NREL blind code comparison the present results showed the overall best agreement with experimental measurements. Based on this, it is of great interest to demonstrate the quality that can be obtained in 3D CFD rotor computations. All six cases we present have 0° yaw angle and 3° tip pitch angle. All computations are performed as rotor‐only computations, excluding the tower and nacelle. In this article we compare computed results and measurements in the form of shaft torque, flap and edge moments, aerodynamic coefficients and pressure distributions as a function of wind speed. The spanwise force distributions are compared with measurements for all wind speeds, along with the pressure distributions at five spanwise positions. Finally, we show how 3D CFD computations can be used to extract information about three‐dimensional aerodynamic effects. Copyright © 2002 John Wiley & Sons, Ltd.
Dimensions and composition of eggs from captive bustards (Gruiformes: Otididae): houbara (Chlamydotis undulata), rufous‐crested (Eupodotis ruficrista), and kori (Ardeotis kori)
Authors: Anderson Susan J. , Deeming Denis C.
Published: October 2002

This study sought to increase understanding of the size and composition of eggs from two subspecies of houbara bustard (Chlamydotis undulata macqueenii and C. u. undulata). Eggs from the rufous‐crested bustard (Eupodotis ruficrista) and kori bustard (Ardeotis kori) were also examined for comparison. Infertile eggs were collected from captive birds; egg mass and linear dimensions were recorded, and egg component masses were determined wet and dry. Significant differences were observed in the composition of the eggs from the two houbara subspecies. Despite being smaller in size, eggs from the macqueenii subspecies had a relatively larger yolk (and relatively less albumen) than eggs from the undulata subspecies. The relative composition of the rufous‐crested and kori bustard eggs showed patterns similar to that of the undulata eggs. For the houbara bustards, changes in initial egg mass (IEM) were associated with changes in egg length more than egg breadth, and changes in egg length and breadth appeared to be due more to increases in albumen mass than to increases in yolk mass. Zoo Biol 21:337–346, 2002. © 2002 Wiley‐Liss, Inc.
Electron‐microscopical localization of chloroplast proteins by immunogold labelling on cryo‐embedded spinach leaves
Authors: Adler Klaus , Arkona Christoph , Manteuffel Renate , Süss Karl‐Heinz
Published: October 2002

Cryo‐substituted spinach leaf pieces, embedded in LR‐White resin by chemical polymerization at low temperature, were used to localize enzymes within chloroplasts by immuno‐electron microscopy. Employing monospecific antibodies and protein A‐gold as label, the spatial distribution of six chloroplast enzymes was investigated. Statistical methods were used to determine whether each enzyme was bound to the thylakoids. By this means the coupling factor 1 (CF1), ferredoxin‐NADP+ reductase, sedoheptulosebisphosphatase, and ribulose‐5‐phosphate kinase were found to be membrane‐associated. In case of glyceraldehyde‐3‐phosphate dehydrogenase the label was only weak and an unequivocal determination of its location was not possible. In contrast, ribulosebisphosphate carboxylase was randomly distributed throughout the chloroplast.
Combined biochemical and immunocytochemical analyses of postmortem protein deimination in the rat spinal cord
Authors: Asaga Hiroaki , Senshu Tatsuo
Published: October 2002

Immunocytochemical staining of citrulline‐containing proteins, i.e. products of endogenous peptidylarginine deiminase (EC 3.5.3.15) reaction, has been performed by chemical modification of citrulline residues in situ, followed by probing with IgG specific to the modified residues. Rat spinal cords that had been preincubated in vitro to accelerate the enzyme reaction were used as samples. Not only astrocytes but also the cytoplasm of some large neurons were stained. Usefulness of the method for studying nervous tissue damage was suggested.
The involvement of the cytoskeleton in regulating IP3 receptor‐mediated internal Ca2+ release in human blood platelets.
Authors: Bourguignon Lilly Y. W. , Iida Naoko , Jin Hengtao
Published: October 2002

In this study we have used saponin to permeabilize platelet membranes in order to test directly the involvement of IP3 in regulating internal Ca2+ release, and to measure IP3 binding to its receptor. Our results indicate that platelet vesicles release Ca2+ as early as 3 seconds after IP3 addition. Using [3H]IP3, we have found that platelets contain a single class of high affinity IP3 binding sites with a Kd of ∼0.20 (± 0.01) nM. Immuno‐blotting shows that platelets contain a 260 kDa polypeptide which shares immunological cross reactivity with brain IP3 receptor. Immunofluorescence staining data indicate that the IP3 receptor is preferentially located at the periphery of the platelet plasma membrane. Most importantly, both IP3 binding and IP3‐induced Ca2+ release activities are significantly inhibited by cytochalasin D (a microfilament inhibitor) and colchicine (a microtubule inhibitor). These findings suggest that the cytoskeleton is involved in the regulation of IP3 binding and IP3 receptor‐mediated Ca2+ release during platelet activation.
Localization of MPM‐2 recognized phosphoproteins and tubulin during cell cycle progression in synchronized Vicia faba root meristem cells.
Authors: Binarova P. , Cihalikova J. , Dolezel J.
Published: October 2002

MPM‐2 antibody reacts with a subset of mitotic phosphoproteins. We followed localization of MPM‐2 immunoreactive material and localization of microtubules during cell cycle progression in a highly synchronous population of Vicia faba root meristem cells and isolated nuclei. The MPM‐2 antibody labelling showed significant cell cycle dependence. MPM‐2 nuclear reactivity was weak and homogeneous in G1 and S phase of the cell cycle and became stronger and heterogeneous during G2, resembling staining of the nuclear matrix, with maximum staining at the G2/M interface. Similarly the staining intensity of nucleoli increased from late G1 phase to nucleoli dispersion in early prophase. During mitosis MPM‐2 immunoreactivity was associated with spindle configurations and the brightest signal was localized in kinetochores from prophase to metaphase.
Steroidogenesis in immature chicken ovary. Hormonal stimulation of adenylyl cyclase system by luteinizing hormone and β‐adrenergic agonists
Authors: Gonzalez Claudia B. , Cantore Maria L. , Passeron Susana
Published: October 2002

The presence of a hormonally responsive adenylyl cyclase in the immature chicken ovary was investigated. We found that there was a highly significant difference (P< 0. 05) between basal and LH and catecholamine activatable activities. In addition, the basal activity was stimulated by NaF, forskolin and the non‐hydrolyzable GTP analogue guanosine‐5′‐(β, gamma;‐imido)‐triphosphate (GMPP(NH)P. The action of catecholamines on cyclic AMP and progesterone production was also investigated and compared to that of LH. The stimulatory effect of isoproterenol on cyclic AMP and progesterone production was significantly higher (P< 0.05) than that of LH. The β‐adrenergic antagonist propranolol caused complete inhibition of the stimulatory action of catecholamines. Progesterone accumulation induced by LH or isoproterenol was synergistically augmentated by the simultaneous presence of both inducers.
Ecto‐ATPases and 5′‐nucleotidases in the caveolae of smooth muscle. Enzyme‐histochemical evidence may indicate a role for caveolae in neurotransmission.
Authors: Kittel Agnes , Bácsy Ernö
Published: October 2002

We have demonstrated the localization of ecto‐Ca‐ATPase and 5′‐nucleotidase activity in the caveolae of smooth muscle cells of guinea pig vas deferens and the ileum longitudinal muscle strips with a cerium‐precipitation enzyme‐cytochemical method. The activities seemed to be strongest in the caveolae. Since the simultaneous presence of the 5′‐nucleotidase activity supports the hypothesis that this ecto‐Ca‐ATPase activity does not have a pump function, but, together with 5′‐nucleotidase, may play a role in neurotransmission, these specific membrane invaginations, the caveolae, have a functional relationship with transverse tubules of striated muscle.
Expression and localization of mRNA encoding 16 kD subunit of vacuolar H+‐ATPase in rat brain
Authors: Numata Masayuki , Ohkuma Shoji , Iseki Shoichi
Published: October 2002

The 16 kD subunit of vacuolar H+‐ATPase (V‐ATPase) is essential for pumping protons into intracellular organella. Northern blot analysis revealed that the 16 kD subunit of V‐ATPase is abundantly expressed in rat brain, and that the amount of transcripts is higher in the postnatal 15 days than in the adult age. On in situ hybridization, the mRNA signal for 16 kD subunit of V‐ATPase was detected widely over the brain tissues of both adult and postnatal rats, with higher intensity in most of the gray matters located in the cerebellar cortex, hippocampus, thalamic nuclei, pontin nuclei, and olfactory bulb. In contrast, the signal in the cerebral cortex was preferentially enriched in the surface layers in the postnatal 10 days but was distributed diffusely and weakly over the entire layers thereafter. In all regions of brain, the mRNA signal was located predominantly in the neurons rather than in the glial components.
Reversible macrophage differentiation induced in a new human myeloid cell line by gamma interferon.
Authors: Pintér Claudia , Magnani Ivana , Paini Cinzia , Clivio Alberto
Published: October 2002

A new cell line was established from the bone marrow of a patient with chronic myeloid leukemia. The cells were attributed an intermediate myeloid phenotype on the basis of their cytochemical features and membrane antigen expression. These cells respond to both chemical and physiological activators of the signal transduction pathways with growth arrest and phenotype changes. Macrophage maturation can be induced in a fraction of the cells by gamma‐interferon (γ‐IFN). Cells are however recruited again into the cell cycle by recultivation in γ‐IFN‐free medium: variants unresponsive to γ‐IFN, and others which show either reversible or irreversible differentiation were isolated from the original cell line by cloning and sib‐selection. These clones can be used to investigate the relationship between γ‐IFN response pathways and cell proliferation.
Reduction of extracellular superoxide dismutase activity by decapeptide derived from FGF‐receptor
Authors: Willems Jean , Noppe Wim , Slegers Herman
Published: October 2002

Several synthetic decapeptides containing an HAV tripeptide motif were tested for their ability to modulate the enzymatic activity of rat extracellular SOD, an enzyme which also contains an HAV motif. Out of nine decapeptides that were tested, only a FGF‐receptor derived peptide was active as a negative modulator of enzyme activity. These results strenghten the thesis that HAV motifs are not only involved in homophilic interactions and suggest that soluble FGF‐receptor molecules might moderate the activity of extracellular SOD.
Microjet impingement followed by scanning electron microscopy as a qualitative technique to compare cellular adhesion to various biomaterials
Authors: Richards R. Geoffrey , Gwynn Ap Iolo , Bundy Kirk J. , Rahn Berton A.
Published: October 2002

Adhesion of cells to biomaterial surfaces is one of the major factors which mediates their biocompatibility. Quantitative or qualitative cell adhesion measurements would be useful for screening new implant materials. Microjet impingement has been evaluated by scanning electron microscopy, to determine to what extent it measures cell adhesion. The shear forces of the impingement, on the materials tested here, are seen to be greater than the cohesive strength of the cells in the impinged area, causing their rupture. The cell bodies are removed during impingement, leaving the sites of adhesion and other cellular material behind. Thus the method is shown not to provide quantification of cell adhesion forces for the metals and culture plastic tested. It is suggested that with highly adherent biomaterials, the distribution and patterns of these adhesion sites could be used for qualitative comparisons for screening of implant surfaces.
Redistribution of nuclear envelope associated antigen during the mitotic cycle.
Authors: Batova I. N. , Kyurkchiev St. D. , Russev R. , Kehayov I. R.
Published: October 2002

Murine hybridomas were generated to DNA/tight binding proteins complex isolated from the residual nuclear structure following a procedure analogous to that yielding "empty" shells of nuclear envelope. A monoclonal antibody designated 2A8 was selected because of its differential immunostaining of mitotic cells of a synchronized mouse fibroblast cell culture L‐929. The target antigen was rendered insoluble by a sequence of extractions of isolated nuclei of diverse cell types with detergents, urea, DNase I and alkali thus reproducing some solubility properties of proteins constituting an operationally defined residual nuclear matrix. The cognate polypeptide was localized on a subset of proteins of Mr 58‐65 kDa, 70 kDa in isolated fibroblast nuclear matrices. The functional implication of the antigen in mitosis‐related disassembly‐assembly process of the nuclear matrix/envelope was detected. At prophase the antibody decorated the nuclear periphery and nuclear envelope fixed inward filaments. A fibrous network of cytoplasmic localization was stained in metaphase. At anaphase the antigen was dispositioned into peripheral fibrogranular clusters of polar orientation predominantly on one side of the nucleus. Proceeding to telophase a spreading fluorescence was manifested over the entire contour of the nuclear periphery to delineate the reforming nucleus. By immunogold electron microscopy of interphase cells the antigen was identified as evenly distributed in chromatin and interchromatin regions. At initiation of chromosome condensation in mitosis the label was detected predominantly in the chromosomal area.
Insulin‐like growth factors.
Authors: Schmid Christof
Published: October 2002

The insulin‐like growth factors I and II are single chain polypeptides homologous to proinsulin. IGF I and IGF II contribute to cell regulation and stimulate protein synthesis via signaling through type I receptors which are homologous to insulin receptors and activate phosphorylation cascades. IGFs enhance the proliferation of chondocytes and the proliferation of their collagen and proteoglycan matrix; IGFs stimulate longitudinal (endochondral) bone growth. Throughout life, IGFs are constitutvely expressed ubiquitous factors which help to maintain the survival of differentiated cells, Increased expression is found during growth and tissue repair, Six specific binding proteins, IGFBP 1‐6, allow additional tissue compartment specific control of IGF activity; IGFBP production favours storage and IGFBP cleavage leads to activation.
F‐actin in mitotic spindles of synchronized suspension culture cells of tobacco visualized by confocal laser scanning microscopy
Authors: Kengen Harry M. P. , Eygensteyn Jelle , van Amstel Ton N. M.
Published: October 2002

TRITC‐labelled phalloidin was used to visualize F‐actin distribution during mitosis in Nicotiana tabacum BY‐2 suspension cells. Aphidicolin was used to synchronize cell suspensions, which enabled sufficient numbers of mitotic cells to be obtained. F‐actin was present in the spindle, and its orientation seemed to correlate with the known microtubular arrays. The use of confocal microscopy greatly reduced background fluorescence, and therefore fine actin filaments could be observed in spindles previously thought to be devoid of actin.
Gene expression and protein distribution of inter‐α‐trypsin inhibitor in three human hepatoma cell lines.
Authors: Héron Antoine , Borghi Hélène , Callé Aleth , Bourguignon Jeannette , Diarra‐Mehrpour Maryam , Martin Jean‐Pierre , Sesboüé Richard
Published: October 2002

In standard culture conditions, three human hepatoma cell lines, Hep3B, PLC/PRF/5 and HepG2, were characterised by a predominant transcription of only two (H2 and L) among the four genes involved in the synthesis of inter‐α‐trypsin inhibitor (ITI)‐related proteins. Pulse‐chase experiments followed by immunoprecipitation with specific anti‐L and anti‐H ITI antisera showed that the proteins synthesised displayed a restricted L and/or H2 antigenic reactivity. Furthermore, while Hep3B and PLC/PRF/5 lines only synthesised ITI precursors (mainly the L‐form), HepG2 cells were able to secrete an ITI‐like protein. Immunocytochemical analyses substantiated these results with uneven distribution of heavy and light‐chain polypeptide reactivity among the cells. The use of hepatoma cell models for the study of protein synthesis and assembly must therefore be considered cautiously.
Involvement of tubulin in MPP+ neurotoxicity on NGF‐differentiated PC12 cells.
Authors: Cappelletti Graziella , Incani Cristina , Maci Rosalba
Published: October 2002

In vivo, the neurotoxin MPTP is oxidated to MPP+, which is toxic to dopaminergic neurons. In this paper, we have used MPP+ as a tool to evoke neurotoxicity in the PC12 cell line and investigate the intracellular events that are involved. A cytotoxicity test, performed on undifferentiated and NGF‐differentiated PC12 cells, showed that MPP+ is much more toxic on differentiated cells and indicated the suitable range of concentrations for studying the starting events evoked by the neurotoxin. By indirect immunofluorescence we have shown that the localisation of α ‐ and β ‐tubulin in NGF‐differentiated cells was modified by a 24 h treatment with 15 μmol/l MPP+. A biochemical analysis was performed on cell extracts and the results showed that MPP+ treatment induced an increase in α ‐tubulin levels and a decrease in β ‐tubulin levels. These results suggest the involvement of the two microtubule proteins in MPP+ neurotoxicity on NGF‐differentiated PC12 cells.
Transfection of normal human skin fibroblasts with human α1(I) and α2(I) collagen gene constructs and evidence for their coordinate expression
Authors: Hata Ryu‐Ichiro
Published: October 2002

Type I collagen is composed of two α1(I) chains and one α2(I) chain that together form a unique triple helical structure. The genes for these chains are located on different chromosomes but their expression is tightly regulated. In order to investigate the mechanism of regulation of coordinate expression of these genes, I examined conditions for the efficient transfection of normal human skin fibroblasts with luciferase reporter gene constructs containing noncoding region of the first exon and the upper 500 base pairs sequence of the α1(I) or α2(I) gene. Expression ratio of these two reporter gene constructs was two to one, indicating these regions of α1(I) and α2(I) genes contain essential regulatory elements for the coordinate expression of α1(I) and α2(I) genes located on different chromosomes.
THE DENDRITIC CELL: ITS POTENT ROLE IN THE RESPIRATORY IMMUNE RESPONSE
Authors: LAMBRECHT B. N. , PAUWELS R. A. , BULLOCK G. R.
Published: October 2002

The importance of the dendritic cell for the capture of antigens and initiating an immune response is now well recognized. Whereas much is known about their structure and function, their lineage is still not clear. Studiesin vitrohave demonstrated that the regulated maturation of function that occurs in culture explains many of thein vivoevents relating to antigen capture and presentation. The control over maturation and migration of these cells to the immune system is decisive as to whether an immune response is mounted or not. ‘Danger ’ signals provided by conserved bacterial products or by microenvironmental cytokines are important regulators. Dendritic cells have been clearly involved in the development of respiratory disease and our understanding of their involvement will have an impact on our future therapeutic strategies.
EARLY EFFECT OF MOSQUITO LARVAE EXTRACT ON MOUSE CELLS PROLIFERATIONIN VIVO
Authors: RONDEROS JORGE R.
Published: October 2002

It has been demonstrated that mosquito larvae crude extract has an inhibiting effect on the mitotic rate of several mouse cell populations. The sampling period was 16–24h after treatment, when mitotic peak normally occurs. The present paper reports the effect of mosquito larvae crude extract on the proliferation of hepatocytes, renocytes, Lieberkhün crypt enterocytes, and sialocytes. In this case, the sampling period covered the dark phase of the day, during the first 12h after treatment. Colchicine‐arrested metaphases were controlled at 20/04, 00/08 and 04/12 (Time of Day/Time Post Injection). The mitotic rate was significantly increased in hepatocytes and renocytes and inhibited in duodenum enterocytes. In view of the time chosen to administer the treatments and the time elapsed until sampling, we conclude a probable effect of the extract at the G2‐M point of the cell cycle.
IMPLICATION OF INVOLVEMENT OF RAT CHROMOSOME #2 IN SPONTANEOUS TRANSFORMATION OF THE RAT‐2 CELL LINE
Authors: KRISHNAVENI L. , GHOSH S. N.
Published: October 2002

Using anin vitromodel for cell transformation, the relationship between specific chromosomal aberration and phenotypic changes was studied at different passages of Rat‐2 cell line. A marker chromosome resulting from a translocation [t(2;7)] was found to be associated with focus formation in soft agar. Conversely, the loss of this marker chromosome was found to be associated with phenotypic reversion. These results suggest an association of this marker chromosome with phenotypic transformation for the Rat‐cell line.
CONSTITUTIVELY MIGRATING MALIGNANT RAT LIVER EPITHELIAL CELLS PRODUCE A MIGRATION‐STIMULATING ACTIVITY FOR EPITHELIAL CELLS (eMSA)
Authors: ECKSTEIN BARBARA K. , BADE ERNESTO G.
Published: October 2002

Constitutively migrating malignant rat liver epithelial cells obtained by Ha ras transformation exhibit a fibroblastoid phenotypein vitro. The cells deposit the anti‐adhesive extracellular matrix (ECM) protein tenascin into their ECM migration tracks. The serum‐free medium conditioned by these constitutively migrating cells contains an epithelial migration‐stimulating activity (eMSA) that is neither cell‐type‐, nor species‐specific. This eMSA fractionates in the range of 30 to 50kDa and binds to Mono‐Q, Mono‐S, and with low affinity to heparin—Sepharose. The conditioned medium also induces the expression of the serine proteinase inhibitor PAI‐1. Both migration and expression of PAI‐1 are inhibited by cyclic AMP, as previously shown for the migration of the non‐transformed liver epithelial cells induced by several growth factors that act through tyrosine kinase receptors. These results suggest that the eMSA might act through signal transduction pathways similar to those of the growth factors previously studied. It is postulated that the eMSA, through both autocrine and paracrine mechanisms, is at least partially responsible for the malignant phenotype of the transformants.
INVOLUTION OF MOUSE MAMMARY GLANDS DURING WHOLE ORGAN CULTURE OCCURS VIA APOPTOSIS OF EPITHELIAL TISSUE
Authors: CASEY T. M. , CHEN H. , PLAUT K. , CHIU J. F.
Published: October 2002

Apoptosis was measured in mammary glands during whole organ culture, to determine whether regression resulting from hormone withdrawal results in epithelial cell death as in vivo involution. Glands were evaluated for morphology and DNA degradation prior to whole organ culture, after lobulo‐alveolar development and 2, 4, or 6 days after hormone withdrawal. The data indicated that mammary regression during whole organ culture mimics in vivo involution and results in part from apoptosis of epithelial tissue.
ALTERATIONS IN IMMUNOGLOBULIN SYNTHESIS DURING ADRIAMYCIN‐INDUCED APOPTOSIS IN MOUSE HYBRIDOMA CELLS
Authors: MELIKSETIAN M. B. , DAVTYAN T. K. , CHIRKOWA I. V. , ALEXANYAN YU.T. , IGNATOVA T. N.
Published: October 2002

Changes in the immunoglobulin synthesis in mouse hybridoma 1F7cell line following exposure to the anticancer drug adriamycin were studied. It was shown that adriamycin in concentrations up to 0.1μg/ml causes dose‐dependent reversible enhancement of immunoglobulin heavy γ2bchain synthesis, and to a lesser extent, κ light chain synthesis. Enhancement of γ2bheavy chain synthesis accompanies an increase in Ig γ2bmRNA levels. Enhancement of DNA‐binding activity of another B‐cell specific protein, octamer transcription factor Oct‐2 was also observed. Cell cycle analysis revealed accumulation of the ADR‐treated cells in G2/M phase of cell cycle. These changes in hybridoma cells preceded the onset of internucleosomal DNA fragmentation and appearance of morphological characteristics of apoptosis. These findings suggest, that differentiation‐related processes occur during the latent phase of apoptosis induced by adria‐mycin in mouse hybridoma cells.
CYTOKINE‐ AND NEUROPEPTIDE‐MEDIATED DIFFERENTIATION IN RETINAL PIGMENT EPITHELIAL CELLS IN VITRO
Authors: KISHI HIROKO , MISHIMA HIROMU K. , YAMASHITA UKI
Published: October 2002

To determine the mechanism of growth and differentiation of retinal pigment epithelial (RPE) cells it is important to understand the pathogenesis of several retinal diseases. Recently it has been reported that several cytokines and neuropeptides regulate the growth of RPE cells. In this study, the role of cytokines and neuropeptides in melanin synthesis, which is one indication of the RPE cell differentiation, was examined using chick RPE cells in vitro IL‐1β, TNF‐α, substance P, β‐endorphin and methionine‐enkephalin stimulated the melanin synthesis of RPE cells in a dose‐dependent manner. The most effective concentrations of these agents on RPE cell melanin synthesis were not the same as that for RPE cell proliferation. These results indicate that cytokines and neuropeptides play an important role not only for the growth but also for the differentiation of RPE cells.
PROTOANEMONIN‐INDUCED CYTOTOXIC EFFECTS INEUGLENA GRACILIS
Authors: MARES D. , BONORA A. , SACCHETTI G. , RUBINI M. , ROMAGNOLI C.
Published: October 2002

The changes that protoanemonin, an antimicrobial agent of natural origin, brought about in the algaEuglena graciliswere studied with light and electron microscopy and with flow cytometry. The compound proved lethal for the alga at a dose of 5×10−5m. At the sublethal dose of 3.5×10−5m it caused: marked inhibition of growth; increase in the average cell volume; inhibition of cytokinesis and induction of coenocytic organisms; loss of the primary_articlegellum and stigma. Most nuclei were arrested in the G2/M phase of the cellular cycle. The chloroplasts were still well organized, but there was a conspicuous decrease in carotenoids and chlorophyllsaandbwith a corresponding increase in pheophytins. The multifarious alterations seen in Euglena are discussed on the basis of a possible interaction between this lactone and several enzymatic systems.
INHIBITION OF LACTOGENIC ACTIVITIES OF BOVINE MAMMARY GLAND EXPLANTS BY THE WHEY FRACTION OF BOVINE MILK
Authors: SHAMAY A. , SHINDER D.A , BRUCKENTAL I. , SILANIKOVE N.
Published: October 2002

The regulation of milk constituents, synthesis and secretion in tissue cultures of the bovine mammary gland was altered by a whey fraction of bovine milk. α‐Casein gene expression, casein secretion and fatty acid synthesis were inhibited by the whey fraction in a dose‐dependent manner. The whey fraction inhibited the enhancement activity of prolactin on α‐casein gene expression and fatty acid synthesis, and also inhibited casein secretion to the medium, in explants cultured in a medium with or without prolactin. No effect on the expression of the β‐lactoglobulin gene was found.
CUTICULAR METALS: QUANTIFICATION AND MAPPING BY COMPLEMENTARY TECHNIQUES
Authors: FAWKE JAMES D. , McCLEMENTS JULIAN G. , WYETH PAUL
Published: October 2002

Metal‐replete cuticle was characterised by back‐scattered electron imaging, secondary ion mass spectrometry, proton induced X‐ray emission and SEM‐X‐ray microanalysis. Each technique was found to have singular advantages and limitations for localising and quantifying metal content. Manganese and zinc were found coincident at the mandibular cutting edge of the leaf‐cutting ant Atta sexdens; these two metals were found in different zones within jaws of the ragworm, Nereis virens; while only manganese was found in the jaws of the termite C. cumulans.
HISTOPATHOLOGICAL AND HISTOCHEMICAL CHANGES IN HONEYBEE LARVAE (APIS MELLIFERA L.) AFTER INFECTION WITH BACILLUS LARVAE, THE CAUSATIVE AGENT OF AMERICAN FOULBROOD DISEASE
Authors: GREGORC ALEŠ , BOWEN IVOR D.
Published: October 2002

Morphological, histochemical and cytochemical changes were examined in honeybee larvae after infection with the bacterium Bacillus larvae. The results indicate cell necrosis in the midgut epithelium accompanied by increasing cell vacuolization and nuclear pyknosis following per os inoculation with B. larvae. Many autolysosomes were positive for acid phosphatase. Non‐vacuolar acid phosphatase activity was also found in lysed cell compartments. No such activity was found in regenerative epithelial cells. Degradation of haemocytes, salivary glands and other tissues was also observed. Histochemical analyses after per cutaneous inoculation with B. larvae of three‐ and five‐day‐old honeybee larvae show intense non‐vacuolar acid phosphatase activity followed by disintegration of infected salivary glands, epithelial cell cytoplasm and haemocytes.
ANTHERIDIAL CHROMATIN CONDENSATION FACTOR FROM MALE SEX ORGANS OF CHARA TOMENTOSA
Authors: KAŹMIERCZAK ANDRZEJ , MASZEWSKI JANUSZ
Published: October 2002

Incubation of roots (Melandrium noctiflorum) in crude extracts obtained from maturing male sex organs of Chara tomentosa results in supercondensation of mitotic chromosomes. The observed changes, including a number of ‘secondary effects’, confirm precisely with all those kinds of alterations which are typical of M‐phase cells in antheridial filaments during their progression from the proliferative period of development towards terminal differentiation into sperm cells. Biological assays performed with proteinaceous extracts of maturing antheridia indicate that the activity is confined merely to a fraction containing low molecular (4.5kDa) peptides, termed as ACCF (antheridial chromatin condensation factor). Microchemical tests showed the acidic character of ACCF and its apparent ability to form cross‐links with histones and DNA‐histone complexes, mediated presumably by disulfide bridges. The characteristic punctate distribution of vesicles within the cytoplasm suggests the internalization of rhodamine‐isothiocyanate labelled ACCF (ACCF‐TRITC) by endocytosis, implying possible sequestering and nuclear translocation upon release from the endosomal/lysosomal compartment of the cell.
TEMPORAL‐SPATIAL EXPRESSION OF TWO PARACENTROTUS LIVIDUS CELL SURFACE PROTEINS
Authors: ROMANCINO DANIELE P. , GHERSI GIULIO , GAMBINO ROBERTO , MONTANA GIOVANNA , COSTA CATERINA , DI CARLO MARTA
Published: October 2002

The temporal expression of two cell surface proteins, called BEP1 and BEP4, during Paracentrosus lividus embryonic development was studied. These proteins are found in both monomeric and dimeric forms in egg and embryos and we have established that their specific form is related to their being in the cytoplasm or on the cell surface. The spatial distribution of BEP1 and BEP4 proteins in eggs and embryos was established by whole mount immunohistochemistry. These proteins are located in the animal part of unfertilized and fertilized eggs; thereafter they are much less represented in structures derived from the vegetal cells of the embryo such as the micromeres of the 16 cell stage, the primary mesenchyme of blastula and the gut of gastrula. At the prism stage BEP1 and BEP4 proteins are present to some ectodermal parts and thereafter, at the pluteus stage, to the oral region.
Cisplatin inhibits folic acid chemotaxis and phagocytotic functions in dictyostelium discoideum
Authors: Reddy T.B.K , Chatterjee S.
Published: October 2002

Administration of 100 and 200μg/ml of cisplatin [cis ‐diammine dichloro platinum (II)] for 1h to growing Dictyostelium discoideum cells severely affects folic acid chemotaxis and phagocytotic function in this organism. Following cisplatin treatment, cells show a much lower uptake of FITC labelled bacteria and a reduced plaque forming ability when plated on Eschericia coli seeded normal agar. Folic acid chemotaxis and folate deaminase activity are greatly inhibited in cisplatin‐treated Dictyostelium cells. SDS‐PAGE analysis shows a greater association of actin and myosin with the cell cortex of treated cells. These results have been discussed in relation to cisplatin's known ability to raise the levels of cytosolic calcium.
Establishment and characterization of conditionally immortalized organ of corti cell lines
Authors: Kalinec Federico , Kalinec Gilda , Boukhvalova Marina , Kachar Bechara
Published: October 2002

A culture of cells was isolated from the organ of Corti of 2‐week‐old H‐2Kb‐tsA58 (Immortomouse) transgenic mice. All cells of these mice harbor a mutant of the simian virus 40 A‐gene, encoding a thermolabile large T‐antigen (Tag) protein. At 33°C the Tag protein is functional and induces cell proliferation, but at 39°C it is rapidly denatured and inactivated. Isolated organ of Corti cells growing at 33°C were predominantly small, rounded or fusiform and proliferated rapidly. When moved to 39°C, the cells reduced their rate of proliferation and differentiated into specific morphological phenotypes. Four cell lines were cloned by limiting dilution and characterized by immunofluorescence microscopy and Western blot. The cell lines, named OC‐k1, OC‐k2, OC‐k3 and OC‐k4, have been passaged at least 50 times with retention of a stable phenotype. These cell lines were all positive for the neuroepithelial precursor cell marker nestin and for the inner ear cell marker OCP2. In addition, the cells showed reactivity to epithelial and neuronal cell markers, but with a pattern of protein expression different for each clone and different between cells of the same clone growing at 33°C or 39°C. Some of the clones exhibited asymmetric cell division which is a characteristic commonly ascribed to stem cells. These cell lines can be used advantageously to study mechanisms and signals involved in the control of cell differentiation and morphogenesis of the mammalian inner ear and to isolate inner ear specific proteins.
UVC‐INDUCED CELL DEATH OF IL‐2‐DEPENDENT HUMAN LYMPHOCYTES
Authors: Radziszewska E. , Piwocka K. , Skierski J. , Sikora E.
Published: October 2002

We compared the in vitro propensity of human IL‐2‐dependent lymphocytes (young proliferating and senescent non‐proliferating), and resting peripheral blood lymphocytes (PBLs) to undergo UVC‐induced apoptosis. The activities of AP‐1 (activator protein‐1), CRE (cAMP response element) and OCT‐1 (octamer‐1) transcription factors in all lymphocytes were also assessed. At 24h after UVC treatment, half of young proliferating T lymphocytes and about a quarter of PBLs and senescent non‐proliferating cells were apoptotic, as shown by flow cytometry. However, only in young lymphocytes were both typical DNA ‘ladder’ and Bcl‐2 downregulation evident. The AP‐1 transcription factor was activated by UVC in IL‐2‐dependent young and senescent, but not resting lymphocytes. Taken together, the data show different propensities of resting, proliferating and senescent human lymphocytes to undergo UVC‐induced apoptosis and AP‐1 activation.
RECEPTOR‐BOUND uPA IS REVERSIBLY PROTECTED FROM INHIBITION BY LOW MOLECULAR WEIGHT INHIBITORS
Authors: Dyer Kimberly D. , Linz‐Mcgillem Laura A. , Alliegro Mary Anne , Alliegro Mark C.
Published: October 2002

Urokinase‐type plasminogen activator (uPA) plays a ubiquitous role in cell migration and invasiveness. Amiloride, a competitive inhibitor of uPA, can inhibit endothelial cell (EC) outgrowth during angiogenesis. To address the question of whether amiloride blocked angiogenesis by inhibiting uPA, we undertook a study of uPA expression in sprouting EC in vitro and the effects of amiloride on both enzymatic and morphogenetic activity. As expected, amiloride inhibited soluble uPA (suPA) with an IC50 of 45–85μm, however, receptor‐bound uPA (rbuPA) from the sprouting EC was insensitive to amiloride. Removal of uPA from its receptors confers sensitivity to inhibition by amiloride suggesting that a reversible conformational change may mediate the insensitivity of rbuPA to amiloride and its analogs. In summary, we found no evidence to support the hypothesis that amiloride blocks capillary outgrowth by inhibition of uPA, but were able to successfully demonstrate a functional difference between two physiological forms of this important matrix‐degrading enzyme.
Causes of Two Patterns of Lichen Zonation on Cobbles in the Negev Desert, Israel
Authors: Kidron Giora J.
Published: October 2002

Two patterns of lichen zonation on cobbles were observed in the Negev Desert, Israel: growth on the top of the cobble and growth on the cobble margins. The causes of the different patterns are examined. Microscopic examinations did not reveal any textural or structural differences between the top and the margins of each cobble, excluding the possibility that mineralogical differences are responsible for the patterns observed. Field measurements have, however, shown a significant difference in the quantities of average daily dew, with the top of the cobbles receiving approximately double the quantity received at the margins. These results were consistent on all cobbles examined, loose as well as partially embedded cobbles. In addition, field observations following rain noted a greater moistness at the margins of partially embedded cobbles. This phenomenon, also observed following sprinkling experiments, was explained by water capillary rise. Whilst the top dwelling pattern may be explained by the significantly larger quantities of dew on the top of the cobble, the margin-dwelling pattern may be explained by greater moistness at the cobble-soil interface due to water capillary rise. Providing that the threshold moisture duration is met, lichen colonization may be expected. An estimated annual daylight moisture duration of approximately 260-320 h is thought to be necessary for lichen growth in the Negev. The findings may assist in evaluating weathering rates and paleoclimate reconstruction.
Is Obsidian Hydration Dating Affected by Relative Humidity?
Authors: Friedman Irving , Trembour Fred W. , Smith George I. , Smith Franklin L.
Published: October 2002

Experiments carried out under temperatures and relative humidities that approximate ambient conditions show that the rate of hydration of obsidian is a function of the relative humidity, as well as of previously established variables of temperature and obsidian chemical composition. Measurements of the relative humidity of soil at 25 sites and at depths of between 0.01 and 2 m below ground show that in most soil environments, at depths below about 0.25 m, the relative humidity is constant at 100%. We have found that the thickness of the hydrated layer developed on obsidian outcrops exposed to the sun and to relative humidities of 30-90% is similar to that formed on other portions of the outcrop that were shielded from the sun and exposed to a relative humidity of approximately 100%. Surface samples of obsidian exposed to solar heating should hydrate more rapidly than samples buried in the ground. However, the effect of the lower mean relative humidity experiences by surface samples tends to compensate for the elevated temperature, which may explain why obsidian hydration ages of surface samples usually approximate those derived from buried samples.