bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth kinetics of the granulosa cell population in ovarian follicles: an approach by mathematical modelling
Authors: Cleément F. , Gruet M. A. , Monget P. , Terqui M. , Jolivet E. , Monniaux D. 
Published: May 2008

AbstractThis paper describes, from a mathematical viewpoint, the cellular changes in the granulosa of ovarian follicles during their terminal development. A dynamic model takes into account the processes of (1) cell division, (2) exit from the cell cycle towards differentiation, and (3) apoptotic cell death. Proliferative cells leave the cycle in an irreversible way. The risk of entering apoptosis applies to non‐cycling cells. Changes in the cell numbers and in the growth fraction are derived from differential equations. The transitions between the different cell states are ruled by time‐dependent rates. Numerical applications of the model concern ovulating and degenerating ovarian follicles in the ewe. The main feature of the ovulating case is the progressive exhaustion of the proliferating compartment for the benefit of the non‐cycling cells. From an initial mainly proliferative state the granulosa progressively switches to a highly differentiated state, so that the growth fraction continuously decreases. In the atretic cases, the pattern of changes in the total viable cell number is influenced by the follicular age at the onset of the apoptotic process and by the intensity of the cell death rate. As apoptosis affects the non‐cycling cells, the growth fraction is no longer strictly decreasing. The sensitivity of the model to the parameters is studied in a more general framework than the granulosa cell population.
A polymerase chain reaction assay for simultaneous detection and quantitation of proto‐oncogene and GAPD mRNAs in different cell growth rates
Authors: Goswami P. C. , Albee L. D. , Spitz D. R. , Ridnour L. A. 
Published: May 2008

AbstractA reverse transcriptase followed by a polymerase chain‐reaction (RT‐PCR) assay was developed for the simultaneous detection and quantitation of proto‐oncogene (c‐fos and c‐myc) mRNAs using an internal standard mRNA glycer‐aldehyde‐6‐phosphate dehydrogenase (GAPD). Total cellular RNA was reverse transcribed and PCR amplified with oligonucleotide primers specific to GAPD and either c‐fos or c‐myc genes. In contrast to Northern blot analysis, the RT‐PCR assay is rapid and sensitive enough to quantitate specific proto‐oncogene levels from as little as 12–25 ng of total cellular RNA. The reliability of the assay was tested by measuring c‐fos and c‐myc expression in C3H 10T1/2 mouse embryo fibroblast cells under two different growth states: (a) quiescent cell entry into the proliferative cycle, and (b) plateau phase. Furthermore, the assay was used in measuring variations in c‐fos or c‐myc expression in HA‐1 hamster cells following exposure to the cellular stressing agent, nitric oxide. In serum‐stimulated cells, the RT‐PCR measurements of transient increase in c‐fos (16‐fold at 30 min) and c‐myc (10‐fold at 1 h) mRNA levels were comparable to previously reported results in the literature using a Northern blotting assay. In addition, a two‐ to fivefold increase in c‐fos mRNA levels was observed in plateau phase cells when compared to log phase growth. Furthermore, a transient increase in c‐fos mRNA levels (threefold at 2 h) was also observed following cells’ exposure to the stressing agent nitric oxide. These results suggest that the multiplex RR‐PCR assay represents a significant improvement over current methods to quantitate specific cellular mRNAs under different growth conditions or following environmental insults.
A novel growth stimulating activity from BRL‐3A cell conditioned medium
Authors: Xu S.‐Q. , Sell C. , DuBois G. C. , Baserga R. 
Published: May 2008

AbstractThe R– cell line is a 3T3‐like cell line originating from mouse embryos with a homozygous disruption of the type 1 insulin‐like growth factor receptor (IGF‐IR) genes. Although R– cells cannot grow at all in serum‐free medium (SFM) supplemented by several known growth factors, either singly or in combination, they are able to grow in 10% serum, albeit at a reduced rate. These findings suggested that serum contains an unknown, or unidentified, growth factor that can promote cell growth even in cells devoid of IGF‐IRs. In an effort to identify such growth factor, we searched, using R– cells, for a growth and DNA synthesis stimulating activity in SFM conditioned by different cell lines. We found that the BRL‐3A cell line secreted an activity capable of stimulating DNA synthesis and cell proliferation in R– cells. This activity (which is concentration‐dependent) can be collected and concentrated by ultrafiltration, it is heat‐labile, proteinase K‐sensitive and has a size larger than 10 kDa. Because of the resistance of R– cells to stimulation by known growth factors, we believe that this activity is due to a novel polypeptide secreted by BRL‐3A cells. Further characterization of the active component(s) is in progress.
Production of Cytokinin‐like Substances by Cylindrocarpon destructans (Zins.) Scholt. Isolates Pathogenic and Nonpathogenic to Fir (Abies alba Mill.) seedlings
Authors: Strzelczyk E. , MariaKampert  
Published: May 2008

AbstractThe production of cytokinin‐like substances by different strains of Cylindrocarpon destructans either pathogenic or non pathogenic to fir (Abies alba Mill.) was studied. The cytokinins were extracted from the fungal culture media and separated by means of column chromatography. The biological activities in different fractions were assayed by callus growth of soybean (Glycine max Merill var. Acme). The amount of these substances was calculated on the basis of fresh weight of callus obtained from cultures containing authentic cytokinin.Cytokinin‐like substances were detected in 5 of 6 pathogenic isolates tested and in 2 of 5 non‐pathogenic isolates.On the basis of their occurrence in particular column fractions, most of the substances seem to be identical or similar to zeatin and zeatin riboside. In addition the fungi studied produced other, not identified cytokinin‐like substances. The synthesis of Ri P can not be excluded. However the method applied did not allow to separate Ri P from zeatin and zeatin riboside.
Detection of Four Seed‐borne Plant Viruses by the Enzyme‐Linked Immunosorbent Assay (ELISA)
Authors: Faris‐Mukhayyish S. , Makkouk K. M. 
Published: May 2008

AbstractThis study was conducted to evaluate the sensitivity of the ELISA technique in detecting four economically important viruses, namely barley stripe mosaic (BSMV), cucumber green mottle mosaic (CGMMV), bean common mosaic (BCMV), and squash mosaic (BSMV) viruses in single seeds as well as in batches of barley, cucumber, bean and squash seeds, respectively. Results indicated the suitability of the technique in detecting the above viruses in single germinated seeds or embryos. Accordingly, seed transmission rates of BSMV, CGMMV, BCMV and SqMV were found to be 67 %, 17%, 17% and 12%, respectively. In artificially contrived mixtures of infected: healthy seeds or embryos, BSMV, CGMMV, BCMV and SqMV were successfully detected at ratios of 1 : 500, 1 : 25, 1 : 10 and 1 : 10, respectively. Sensitivity of detection was increased in the ease of BSMV by using germinated rather than ground dry BSMV‐infected barly seeds; and in the case of SqMV, by using whole germinating emybryos rather than coleoptiles only. Trials on re‐using the enzyme‐γ‐globulin conjugate indicated that CGMMV conjugate used once can be re‐used with little loss in reactivity.
Phytophthora cinnamomi: the Dynamics of Chlamydospore Formation and Survival
Authors: Weste Gretna 
Published: May 2008

AbstractChlamydospore activity was investigated by inoculating 10 day old seedlings of Lupinus angustifolius with Phytophthora cinnamomi. Infected roots were excised and buried in 4 non‐sterile media: – glass beads, gravel, sand or soil at different water potentials and incubated at 22°C. Roots were examined and chlamydospores counted initially and after 10, 20 and 30 days. Large numbers of spores formed in the roots buried in the various media. Spore formation was rapid in glass beads and gravel, and slower in soil, but more chlamydospores survived the 30 day period when roots were buried in soil.Nylon mesh squares 1 cm2were inoculated with 38 chlamydospores and buried in the same 4 media. 70–100% of chlamydospores germinated and colonised 90–100% of the mesh, producing mycelia and an increased number of chlamydospores. In some instances there was a ten‐fold increase in spore numbers and numbers were still increasing at 28 days. Maximum numbers and maximum survival occurred on mesh buried in soil. The role of the chlamydospores is considered, as that of a dynamic unit with a saprobic phase in the life cycle of the fungus which is independent of host, and has the capacity to increase both population density and distribution of the pathogen.
Investigations on Transmission of Grapevine Leafroll, Yellow Speckle and Fleck Diseases by Dodder
Authors: Woodham R. C. , Krake I. R. 
Published: May 2008

AbstractAttempts were made to transmit the infective agents of leafroll, yellow speckle, and fleck diseases from infected grapevmes to several herbaceous species and to healthy vines using dodder (Cuscuta campestris). Dodder transmitted leafroll to all and fleck to half of the respective receptor vines, but none of the three dieases were transmitted to herbaceous plants including Chenopodium, Gomphrena and Nicotiana species, Cowpea, Bean, Cucumber, Squash and Petunia. Suggested transmission of yellow speckle to vine was inconclusive because this disease may have been spread naturally.
Verstärkung der antiphytoviralen Wirkung von 2,4‐Dioxohexahydro‐l,3,5‐triazin durch Kombination mit Verbindungen mit Guanidinstruktur
Authors: Schuster G. 
Published: May 2008

Abstract Intensified antiphytoviral activity of 2,4‐dioxohexahydro‐l,3,5‐triazine by combination with guanidines Combined application of the antiphytoviral compound 2,4‐dioxohexahydro‐l,3,5 triazine (DHT) and different guanidines (GDs) that were either unsubstituted or substituted only by low‐molecular substituents reduced the concentration of potato virus χ (PVX) in leaves or Nicotiana tabacum L. cv. Samsun much more than application of either agent alone. In secondarily PVX‐infected leaves, the activity of 2,4‐dioxohexahydro‐ 1,3,5‐triazine was increased by a larger number of GDs and to a greater degree than in inoculated ones. The activities of GDs against tobacco mosaic virus (TMV) in Nicotiana tabacum L. cv. Samsun as well as against brome grass mosaic virus (BRV) in Hordeum vulgare L. cv Vogelsanger Gold were only insignificantly increased by combination with DHT. On the other hand, in experiments with so‐called identical potato eye cuttings, in which several eye cuttings were obtained from each potato tuber, one serving as a control and the others being treated with DHT, N‐cyano guanidine or a combination of these substances, the number of cuttings with symptoms of potato leaf‐roll virus (PLRV) could be much more greatly reduced by the combination than by the individual preparations. The number of cuttings with symptoms of potato virus Y and potato virus A was significantly reduced by treatment with the combined preparation, but not by treatment with DHT or N‐cyano guanidine alone. Additional investigation with N‐cyano‐GD, and, beside this, with acetyl‐GD and N N′ N triamino‐GD indicated a close correlation between the diminution of numbers of potato eye cuttings with virus symptoms and the increase in tuber weight. The greater the reduction in the number of cuttings showing virus symptoms, the greater was the increase in tuber weight. These relationships were observed even in those cases where controls had been treated with ammonium nitrate solutions whose N contents equivalent to the N contents of the preparations. The observed effects of the preparations therefore are not attributable to N‐fertilizing effects.
The Use of Enzyme‐Linked Immunosorbent Assay (ELISA) for Detection of Cacao Swollen Shoot Virus (CSSV) in Theobroma cacao
Authors: Sagemann W. , Paul H. L. , Adomako D. , Owusu G. K. 
Published: May 2008

AbstractCacao swollen shoot virus (CSSV) was readily detected in different parts of Theobroma cacao using the ELISA technique. Different plant tissues contained varying amounts of CSSV; highest concentrations were found in leaf lamina. Methods to preserve the serological activity of CSSV were evaluated, and best results obtained with samples stored in a buffer or freeze‐dried.
Acetone Inhibition of Rhizoctonia solani Growth
Authors: Madkour M. A. , Abou‐Taleb E. M. , Okasha A. M. 
Published: May 2008

AbstractAcetone (5% v/v) inhibited growth of four isolates of Rhizoctonia solani which differ in their pathogenicity on squash seedlings. Acetone (5% v/v) showed best inhibition on the most aggressive isolate 4 followed by the less aggressive ones (1, 2 and 3, respectively); IAA had no effect on the growth of all R. solani isolates compared to the controls.
Number of Colonies Produced by 22 Isolates of Powdery Mildew on Primary Leaves of 10 Barley Cultivars
Authors: KimChoong Hoe , Hermansen J. E. 
Published: May 2008

AbstractPrimary leaves of 10 barley cultivars were uniformly inoculated with 22 virulent powdery mildew isolates using a jet spore trap. The number of colonies per unit area leaf was counted. Significant differences in number of colonies among cultivars were found, indicating different degrees of susceptibility among cultivars. While cultivars were rather consistent in their rankings for number of colonies produced by most isolates, interactions between some cultivars and isolates were found. In spite of great differences in geographical origin of cultivars and isolates, the interactions were not associated with origin.
Differential Responses of Erysiphe polygoni Conidia to Living and Non‐living Substrata
Authors: Singh U. P. , Singh H. B. 
Published: May 2008

AbstractConidial germination and appressorium formation of Erysiphe polygoni on living and non‐living substrata have been studied. Among living hosts, peelings from bulbs and leaves of Allium sativum and Allium cepa, or from stems of Azadirachta indica and rhizomes of Curcuma longa supported good germination. Zingiber officinale rhizome peelings inhibited germination. Germination and appressorium formation were maximum on the host (Pisum sativum) as compared to some other leguminous hosts. Little morphological variation was noticed among appressoria developed on various substrata, although they differed in size. Conidial germination was enhanced in leaf extract of pea.
m‐Hydroxyphenylacetic and m‐Methoxyphenylacetic Acids of Rhizoctonia solani: Their Effect on Specific Root‐Nodule Activity and Histopathology in Soybean
Authors: Orellana R. G. , Mandava N. B. 
Published: May 2008

Abstractm‐Methoxyphenylacetic acid (m‐OMePAA), a derivative of m‐hydroxyphenylacetic acid (m‐OHPAA), having the same chemical composition as that phytotoxic compound produced in culture by Rhizoctonia solani, a fungal pathogen of soybean, reduced growth and symbiotic N2‐fixation activity of ‘Tracy’ soybeans in soil: perlite at 1.5 × 10‐4 M, the lowest concentration used. At twice this concentration m‐OMePAA was strongly teratogenic and caused root hypertrophy and root fasciation. At 1.2 × 10‐3 M, m‐OMePAA nearly suppressed seed germination. m‐OMePAA at the minimum concentration used and equivalent concentrations of the culture filtrate fraction (m‐OHPAA and m‐OMePAA) caused cytopathological and histopathological disturbances in the nodule central tissue, extrusion of the nucleoli, and abnormal nuclci. The data indicate that these phytotoxic compounds of R. solani are involved in nodule impairment and reduced N2‐fixation in soybean.
Ultrastructural Studies of the Interaction Between Trichoderma spp. and Plant Pathogenic Fungi
Authors: Elad Y. , Barak Rina , Chet I. , Henis Y. 
Published: May 2008

AbstractThe uhrastructural changes during parasitism of the biocontrol agents Trichoderma harzianum and T. hamatum, were observed under a transmission electron microscope. Electron micrographs show that during the interaction of Trichoderma spp. with either Sclerotium rolfsii or Rhizoctonia solani the hyphae of the parasites contact their host, and then enzymatically digest their cell walls. Extracellular fibrillar material is deposited between the interacting cells. Parasite organelles, e.g. mitochondria, vesicles and dark osmiophilic inclusions, accumulate in the parasitizing cells. In response to the invasion, the host produces a sheath matrix which encapasulates the penetrating hypha and the host cells become empty of cytoplasm.
Hyperparasitism of Aphanocladium album on Aecidiospores and Teliospores of Puccinia graminis f. sp. tritici
Authors: Koç N. K. , Forrer H. R. , Défago G. 
Published: May 2008

Abstract Aphanocladium album invaded rapidly 100% of aecidiospores of Puccinia graminis f. sp. tritici resulting in total collapse of the cells. Only 2% of teliospores were invaded. A. album penetrated through the germ pores. The precocious formation of teliospores which occurs immediately following uredial infection may be regarded as defence mechanism of the rust against its hyperparasite.
Phytophthora‐Stammbasisfäule an Dieffenbachia maculate (Erreger: P. mexicana Hots. et Hart.)
Authors: Kröber H. , Kiewnick L. , Richter J. 
Published: May 2008

AbstractStem base rot of Dieffenbachia maculata caused by Phytophthora mexicana During the last years a stem rot of Dieffenbachia maculata (Lodd.) G. Don has been observed in greenhouses of several commercial nurseries, located in different parts of the Federal Republic of Germany. The disease partly caused heavy losses. From all diseased plant parts (stem base, petiole and root) the same fungus could be isolated. It was diagnosed as Phytophthora mexicana Hots, et Hart., which is closely related to P. palmivora (Butl.) Butl. Apparently the former species is recorded for the first time as the causal organism of a Dieffenbachia stem rot and also for the first time in Europe. It is supposed that the fungus was imported to Germany via the Netherlands because all plants had been bought there, which diseased later.
Poinsettia Mosaic Virus — a Tymovirus?
Authors: Lesemann D.‐E. , Koenig R. , Huth W. , Brunt A. A. , Phillips S. , Barton R. J. 
Published: May 2008

Abstract Nicotiana benthamiana was found to be a useful indicator and propagation host for poinsettia mosaic virus (PoiMV). It is not susceptible to poinsettia cryptic virus. The isometric particles of PoiMV sedimented as two components with sedimentation coefficients (s°20,w) of 55 S (“top” component) and 117 S (“bottom” component) and, after fixation, with buoyant densities (g cm‐1) in caesium chloride of 1.29 (“top”) and 1.41 (“bottom”). The A260/A280 ratios were 1.8 and 1.0 for “top” and “bottom” components, respectively. “Top” and “bottom” component particles measured 26 and 29 nm in diameter when mounted in 2 % uranyl acetate; “top” component particles were severely disrupted by 2 % neutral potassium or sodium phosphotungstate or 2 % ammonium molybdate, a phenomenon which is not observed with recognised tymoviruses. The virus particles contained c. 37 % ss‐RNA (mol. wt 2.3° 106) with a base composition of 21 % guanine, 24% adenine, 31 % cytosine and 24% uracil. PoiMV particles were detected in the cytoplasm, vacuoles and nuclei of infected poinsettia and N. benthamiana cells. As in tymovirus infections, the particles within the nuclei were apparently devoid of nucleic acid. The virus induced conspicuous peripheral vesiculation of chloroplasts; the vesicles, however, unlike those induced by recognised tymoviruses, were bound by the inner membrane only of the double chloroplast envelope. PoiMV thus lacks a group‐specific character of the tymovirus group. Serologically it is not related to any of the 17 recognised tymoviruses. It is therefore probably best recognised as a possible member of the tymovirus group.
Transmission, Particle Size and Additional Hosts of the Rhabdovirus Causing Maize Mosaic in Shiraz, Iran1
Authors: Izadpanah K. , Ahmadi A. A. , Parvin S. , Jafari S. A. 
Published: May 2008

AbstractThe rhabdovirus causing maize mosaic in Shiraz, Iran, is transmitted by Ribautodelphax notabilis Logvinenko (Homoptera, Delphacidae). Average size of bullet‐shaped virus particles in negatively stained leaf‐dip preparations of naturally or experimentally infected plants was 81 × 179 nm. The virus is transmitted to wheat and barley causing mosaic and severe stunting. Similar virus particles have been observed in leaf‐dip preparations of naturally infected wheat, barley and Sudangrass. This is believed to be the first record of the involvement of R. notabilis in virus transmission. The relationship of the described isolate with similar viruses infecting gramineous plants is discussed.
A Comparison of Some Serological and Biological Properties of Seven Isolates of Tobacco Ringspot Virus
Authors: Gergerich R. , Asher J. H. , Ramsdell D. C. 
Published: May 2008

AbstractSeven isolates of tobacco ringspot virus (TRSV) from grape, cherry, two cultivars of blueberry, tobacco, soybean and watermelon were compared in this study. The most virulent isolate was from‘Jersey’blueberry and the least virulent isolate was from soybean. The‘Jersey’blueberry isolate and the watermelon isolate could be distinguished serologically from all other isolates. The‘Jersey’blueberry isolate was different in electrophoretic mobility from the soybean and tobacco isolates. A unique technique for comparing the in vitro translation products of three of the TRSV isolates is described.
Development of a Differential Set for the Race analysis of Puccinia hordei Otth.
Authors: Grunewaldt‐Stöcker Gisela 
Published: May 2008

AbstractInvestigations for the race analysis of P. hordei (location Cologne, W.‐Germany) showed, that most of the resistant genotypes in the International differential set with Pa1 to Pa8 were ineffective for that purpose.Out of 80 selected barley genotypes with different degree of resistance against the field‐collection RG 1975 hosts with a strongly differentiating effect were chosen. This was done using three parameters: mean resistance x̄w, its standard deviation x̄w and the range z. They were calculated from evaluating the reaction types of 80 barley genotypes infected with 116 single‐pustule lines of barley brown rust. Eight hosts with strongly differentiating reactions towards the 116 rust lines were composed into a differential set, which could characterize the heterogeneity of the Cologne P. hordei‐population essentially better and more precisely than the International differential set.
The Effect of Temperature, Light and Leaf Age on the Frequency of Appressoria Formation and Infection with Uromyces phaseoli (Pers.) Wint.
Authors: von Alten H. 
Published: May 2008

AbstractThe frequency of appressoria formation is reduced by changed conditions of infection such as adult leaves, higher temperature, or continuous light during penetration. In correlation with the reduced number of appressoria, the infection frequency decreases too. The behaviour of growing germ tubes on the plant surfaces did not show any indication of the fungus being led to the stomates by leaf surface structures. Obviously a recognition signal proceeds from the stomates sometimes helping the fungus to get into the leaf. Probably the gas exchange through the stomates is involved. Carbon dioxide, produced by the leaves in the dark, can build up pH‐gradients towards the stomates as the inoculated leaves are covered with a water film.