bluuebunny/crossref_metadata_2025 huggingface dataset:
The antiproliferative activity of the tetrapeptide Acetyl‐N‐SerAspLysPro, an inhibitor of haematopoietic stem cell proliferation, is not mediated by a thymosin β4‐like effect on actin assembly
Authors: Cheviron N. , Grillon C. , Carlier M.‐F. , Wdzieczak‐Bakala J.
Published: May 2008

Abstract. Acetyl‐N‐SerAspLysPro (AcSDKP), known as a negative regulator of haematopoiesis, has been principally reported as an inhibitor of haematopoietic pluripotent stem cell proliferation. The tetrapeptide sequence is identical to the N‐terminus of thymosin β4 (Tβ4), from which it has been suggested that it may be derived. Recently, evidence was shown that Tβ4 plays a role as a negative regulator of actin polymerization leading to the sequestration of its monomeric form. The structural similarity between the N‐terminus of Tβ4 and AcSDKP has raised the possibility that AcSDKP may also participate in intracellular events leading to actin sequestration.

The effect of Tβ4 on the proliferation of haematopoietic cells was compared to that of AcSDKP. The results revealed that Tβ4, like AcSDKP, exerts an inhibitory effect on the entry of murine primitive bone marrow cells into cell cycle in vitro. Qualitative electrophoretic analysis and quantitative polymerization assays were used to investigate the role of AcSDKP in actin polymerization. AcSDKP does not affect actin assembly at concentrations up to 50 μM, and does not compete with Tβ4 for binding to G‐actin. These results suggest that AcSDKP is not involved in cell cycle regulation via an effect on the process of actin polymerization.
Normal G1/S transition and prolonged S phase within one cell cycle after seeding cells in the presence of an ornithine decarboxylase inhibitor
Authors: Fredlund J. O. , Oredsson S. M.
Published: May 2008

Abstract. We have previously found that DNA replication was affected within one cell cycle after seeding Chinese hamster ovary (CHO) cells in the presence of the polyamine biosynthesis inhibitor 2‐difluoromethylornithine (DFMO). We could, however, not rule out if this was due to an effect on the G1/S transition and/or on DNA synthesis elongation. In the present paper, we use a bromodeoxyuridine‐flow cytometric method to more specifically study the G1/S transition, the S phase length, and the progression of cells from S phase through G2+ M and into G1, after seeding plateau phase CHO cells at low density in the absence or presence of 5 mM DFMO. We report here that DFMO‐induced polyamine depletion increased the length of the S phase within one cell cycle after seeding of CHO cells in the presence of the inhibitor. No effect on the G1/S transition was observed until 2 days after seeding, suggesting that a DFMO‐induced lengthening of the G1 phase occurred later than the effect on S phase progression. These results imply that the G2+ M phase was not prolonged until 2 days after seeding CHO cells in the presence of DFMO.
Insulin‐related peptides and the two‐cell block to development in pre‐implantation mouse embryos
Authors: Parkin M. D. , Schofield P. N.
Published: May 2008

Abstract. In many mammalian embryos development in vitro is arrested after the first zygotic division, a phenomenon known as the two‐cell block. In the mouse several strains exhibit a two‐cell block to further development and it was the purpose of this investigation to determine whether the inability of embryos to progress through the block was due to lack of insulin or insulin‐like growth factors (IGFs) in the medium. Several factors have been implicated in the two‐cell block, amongst which oxidative stress, glucose and missing maternal factors have been examined to date. Because of their anabolic and anti‐apoptotic properties, IGFs are good candidates for such missing maternal factors. Using MF1 strain mice and M16 medium we have examined the effects of IGF‐I, II and insulin on the two‐cell block. No effects were discernable at concentrations known to support development of non‐blocking embryos and we conclude that the IGFs and insulin may be excluded as critical factors in the two‐cell block under the culture conditions used.
Cloning of intestinal phospholipase A2 from intestinal epithelial RNA by differential display PCR
Authors: Keshav S. , McKnight A. J. , Arora R. , Gordon S.
Published: May 2008

Differential display polymerase chain reaction (DD‐PCR) is a powerful technique for comparing gene expression between cell types, or between stages of development or differentiation. Differentially expressed genes may be cloned and analysed further. Here we extend the use of DD‐PCR to analyse differences in gene expression between two complex epithelia: that of the small intestine and of the large intestine. The aim of this study was to identify genes expressed preferentially in Paneth cells. Paneth cells are secretory epithelial cells putatively involved in host defense and regulation of crypt cell proliferation and are found at the base of the small intestinal crypts adjacent to the stem cell zone. Of 34 clones that were analysed, partial sequencing identified two clones related to known Paneth cell products: a homologue of secretory phospholipase A2 (clone B1) and a homologue of a neutrophil defensin (clone C5). B1 was strongly expressed in Paneth cells, as demonstrated by in‐situ hybridization. B1 was also expressed at a lower level in the large intestinal epithelium. A full length B1 cDNA clone was isolated and sequenced, and shown to be highly homologous to type II secretory phospholipase A2 genes, and almost identical to the enhancing factor gene and the putative gene for the MOM‐1 locus. B1 expression is limited to the intestinal tract, and we propose that it be designated intestinal phospholipase A2, or i‐PLA2. The method we describe is well suited to the rapid identification of genes expressed exclusively or predominantly in Paneth cells.
Unbalanced growth in mouse cells with amplified dhfr genes
Authors: Snapka R. M. , Ge S. , Trask J. , Robertson F.
Published: May 2008

When grown in the absence of methotrexate, cells carrying unstably amplified dihydrofolate reductase (dhfr) genes have a growth disadvantage that is a function of their level of gene amplification. Although this growth disadvantage is thought to drive the loss of unstably amplified dhfr genes in the absence of methotrexate, its mechanism is not understood. The present studies of murine cell lines with different levels of dhfr gene amplification demonstrate that such cells experience increased unbalanced growth (excess RNA and protein content relative to DNA content) with increased levels of dhfr gene amplification. Stathmokinetic analysis of a cell line with unstably amplified dhfr genes showed that the unbalanced growth was associated with a very low rate of G1/S transit, which suggests that amplified DNA sequences may activate a cell cycle checkpoint at the G1/S boundary. Hydroxyurea, which is known to induce rapid elimination of amplified genes at sub‐cytotoxic concentrations, also inhibits the cell cycle at the G1/S transition and causes unbalanced growth. Earlier work has shown that hydroxyurea selectively targets those cells within the heterogeneous drug resistant cell populations which have the highest amplified gene dosage. The finding that unstable gene amplification and hydroxyurea have similar effects on the cell suggests that hydroxyurea may achieve this selective targeting by pushing those cells with the highest levels of gene amplification over a critical stress threshold to cause growth arrest or cell death.
Immunoreactivity to MIB‐1 in breast cancer: methodological assessment and comparison with other proliferation indices
Authors: Benini E. , Rao S. , Daidone M. Grazia , Pilotti S. , Silvestrini R.
Published: May 2008

The recent availability of the monoclonal antibody MIB‐1 (which is able to detect the human nuclear cell proliferation‐associated antigen Ki‐67 even on formalin‐fixed, paraffin‐embedded sections, microwave‐treated and routinely processed for immunohistochemistry) could open new avenues for validation of the clinical role of tumour cell proliferation on large, consecutive and unselected series of human tumours. However, the routine use of such a marker requires a methodological standardization as well as the comparative assessment of some technical and biological aspects. The MIB‐1 index was determined in parallel samples from 50 consecutive invasive breast carcinomas processed with different fixatives for different times. The median values of MIB‐1 indices following 2, 6 and 24 h of formalin fixation were similar (29.4%, 30.6% and 29.7%, respectively) and consistent with those reported in the literature; squared linear regression coefficients were 0.99. The median values of MIB‐1 indices were markedly lower in Bouin‐fixed, paraffin‐embedded, and in frozen samples (20.0% and 19.8%, respectively), with a poor correlation coefficient with the values detected following formalin fixation (R2=0.456). Moderate and poor correlations were observed between Ki‐67 index and MIB‐1 detected on frozen (rs, 0.78) or formalin‐fixed, paraffin‐embedded samples (rs, 0.47) and a minimal concordance was observed between TLI and MIB‐1 or Ki‐67 (rs, 0.25 and 0.22, respectively). Our results indicate interference of the fixative type on immunoreactivity to MIB‐1 and also suggest that Ki‐67 and MIB‐1 reacted with different epitopes of the same antigen.
3H‐Thymidine labelling index (TLI) as a marker of tumour growth heterogeneity: evaluation in human solid carcinomas
Authors: Becciolini A. , Balzi M. , Barbarisi M. , Faraoni P. , Biggeri A. , Potten C. S.
Published: May 2008

Many studies deal with the analysis of cell kinetic, cytogenetic, biochemical and molecular cell biology parameters to identify prognostic factors relating to tumour growth but all methods use only a small part of the total tumour mass. This study is devoted to the analysis of the heterogeneity of the growth of human solid tumours assaying proliferative activity by means of 3H‐thymidine labelling index (TLI) in a fixed number of samples collected in different areas of the lesion (larynx and colon cancers), or in different lesions of the same subject (breast and bladder cancers). Each sample (at the macroscopic level) was divided into small fragments (at the microscopic level) and proliferative activity was determined. The analysis of variance for hierarchical designs demonstrated that in all cases a high component of the variance is attributable to the subjects and to the fragments whereas the variance attributable to the different areas is very low. The heterogeneity of proliferative activity displays a higher focal variability among the fragments (microscopic level) compared with that among areas (macroscopic level) within subjects, provided an adequate number of fragments and cells are counted. In multiple synchronous carcinoma of the bladder the wide variability of proliferation among the single lesions demonstrated that it is necessary to analyse all the tumours in a subject because each one is characterized by a different cell growth potential.
Laser scanning cytometry (LCS) allows detailed analysis of the cell cycle in PI stained human fibroblasts (TIG‐7)
Authors: Kawasaki M. , Sasaki K. , Satoh T. , Kurose A. , Kamada T. , Furuya T. , Murakami T. , Todoroki T.
Published: May 2008

We have demonstrated a method for the in situ determination of the cell cycle phases of TIG‐7 fibroblasts using a laser scanning cytometer (LSC) which has not only a function equivalent to flow cytometry (FCM) but also has a capability unique in itself. LSC allows a more detailed analysis of the cell cycle in cells stained with propidium iodide (PI) than FCM. With LSC it is possible to discriminate between mitotic cells and G2 cells, between post‐mitotic cells and G1 cells, and between quiescent cells and cycling cells in a PI fluorescence peak (chromatin condensation) vs. fluorescence value (DNA content) cytogram for cells stained with PI. These were amply confirmed by experiments using colcemid and adriamycin. We were able to identify at least six cell subpopulations for PI stained cells using LSC; namely G1, S, G2, M, postmitotic and quiescent cell populations. LSC analysis facilitates the monitoring of effects of drugs on the cell cycle.
Effect of sodium butyrate on human breast cancer cell lines
Authors: Coradini D. , Biffi A. , Costa A. , Pellizzaro C. , Pirronello E. , Di Fronzo G.
Published: May 2008

We have investigated the effects exerted by sodium butyrate (NaBu) on the growth and cell cycle perturbations of four human breast cancer cell lines (MCF7, T47D, MDA‐MB231 and BT20) with different steroid receptor profiles. Moreover, since one of the supposed mechanisms of action for NaBu activity involves the induction of apoptosis, we have studied the effects of NaBu on DNA fragmentation by agarose gel electrophoresis and flow cytometry. In all investigated cell lines, NaBu exerted a time‐ and dose‐dependent inhibition of growth and caused a maximum inhibitory effect (85% to 90%) at the concentration of 2.5 mm. The inhibition was already evident after 3 days of treatment. The antiproliferative effect of NaBu was associated with a persistent block of cells in the G2M phase. The block was associated with apoptosis only in oestrogen‐receptor positive cell lines. The inhibiting effect of NaBu in hormone‐dependent and independent cell lines and its ability to induce apoptosis through a cell cycle perturbation in hormone‐dependent cell lines may have important implications in the treatment of human tumours including breast cancer.
A mathematical model of the regulation of the G1 phase of Rb +/+ and Rb —/— mouse embryonic fibroblasts and an osteosarcoma cell line
Authors: Obeyesekere M. N. , Knudsen E. S. , Wang J. Y. J. , Zimmerman S. O.
Published: May 2008

A mathematical model integrating the roles of cyclin D, cdk4, cyclin E, cdk2, E2F and RB in control of the G1 phase of the cell cycle is described. Experimental results described with murine embryo fibroblasts (MEFs), either Rb +/+ or Rb —/—, and with the RB‐deficient osteosarcoma cell line, Saos‐2, served as the basis for the formulation of this mathematical model. A model employing the known interactions of these six proteins does not reproduce the experimental observations described in the MEFs. The appropriate modelling of G1 requires the inclusion of a sensing mechanism which adjusts the activity of cyclin E/cdk2 in response to both RB concentration and growth factors. Incorporation of this sensing mechanism into the model allows it to reproduce most of the experimental results observed in Saos‐2 cells, Rb —/— MEFS, and Rb +/+ MEFs. The model also makes specific predictions which have not been tested experimentally.
Modulation of the cell kinetics of pig skin by the topical application of evening primrose oil or Lioxasol
Authors: Morris G. M. , Hopewell J. W. , Harold M. , Ross G. A. , Nadejina N. M. , Gusev I. , Flockhart I.
Published: May 2008

The daily topical application of two compounds, a cream containing 10% evening primrose oil (EPO) and Lioxasol (a compound used clinically to treat radiation burns), resulted in increased cell proliferative activity in the skin of female Large White pigs. The effect was most pronounced in the case of the EPO based cream, and was comparable in magnitude with that observed in a previous study on pig skin using orally administered EPO.

There was an increase in the size of the rete pegs in the epidermis by 6 weeks after the start of application of the EPO cream. However, this did not translate into an increase in the total thickness of the viable epidermis (excluding the stratum corneum) due to a reduction in the density of rete pegs, from 2 weeks after treatment. Lioxasol had no overall effect on the size of the rete pegs. The labelling index (LI) of cells in the basal layer of the epidermis of pigs receiving a daily topical application of EPO increased progressively with time from the start of application. The LI was maximal (17.9 ± 2.4%) at the end of the observation period (8 weeks) at which time it was a factor of ∼ 2 higher than in the basal layer prior to treatment. A considerably less marked increase in the LI of the basal layer was seen after the application of Lioxasol. The overall increase was ∼ 20%, relative to the LI in the untreated epidermis.

Labelled cell nuclei were also counted in the papillary dermis. After the application of the EPO cream, no significant increase in the number of labelled cells was observed until week 8, at which time values were approximately twice those in untreated skin. In Lioxasol treated skin the effect on the numbers of labelled cells in the papillary dermis was more immediate, with a ∼ 60% increase at 2 weeks. This enhanced level of labelling was maintained until the end of the observation period of 10 weeks. Studies on the cell kinetics of the skin using the alcohol component of the Lioxasol preparation suggested that alcohol rather than Lioxasol was the most signifiant ingredient. It was concluded that the EPO cream merited further evaluation as a potential modulator of skin response to ionizing radiation.
Demonstration of an Na+/H+ exchanger in mouse keratinocytes measured by the novel pH‐sensitive fluorochrome SNARF‐calcein
Authors: van Hooijdonk C. A. E. M. , Colbers R. M. L. , Piek J. , van Erp P. E. J.
Published: May 2008

In many cell types cytoplasmic alkalization is an early marker for cell activation. An amiloride‐sensitive Na+/H+ exchanger is an important regulator of this process. However, in keratinocytes the existence of a Na+/H+ exchanger nor a proliferation‐associated increase in intracellular pH (pHi) has been demonstrated.

The aim of this study was to investigate whether or not keratinocytes, derived from the BALB/MK cell line, contain a Na+/H+ exchanger and whether cytoplasmic alkalization is proliferation‐associated in these cells. This mouse keratinocyte cell line can easily be switched between a proliferative and a quiescent state under defined culture conditions. The novel pH‐sensitive dye seminaphthorhodafluor (SNARF)‐calcein proved to be very suitable for flow cytometric pHi measurements in BALB/MK cells. Initial measurements of the pHi using a cocktail of the established fluorochromes 2′,7′‐bis(carboxyethyl)‐5,6‐carboxyfluorescein (BCECF) and SNARF‐1 failed because of the differential uptake and binding kinetics of these pH‐sensitive dyes.

Using SNARF‐calcein we were able to show proliferation to be associated with increased pHi. However, culture conditions were critical for these measurements. Our data indicate that the Na+/H+ exchanger is involved in this process, since acid load and pHi‐recovery experiments showed the alkalization to be amiloride‐sensitive.
Should we be ‘pushing meds’? The implications of pharmacogenomics
Authors: BRAY J. , CLARKE C. , BRENNAN G. , MUNCEY T.
Published: May 2008

Medication continues to be the most widely prescribed treatment in the NHS for mental health problems. It has been known for many years that individuals differ in the way they respond to a given pharmaceutical therapy, and one reason for this lies in the genetic variation between individuals. This paper recognizes the impact that pharmacogenomics and pharmacogenetics are having in the field of mental health. Variants in genes that code for the drug metabolizing enzymes in the liver have been found to influence the way in which these enzymes handle psychotropic medication. Individuals can be classified as poor, moderate or extensive metabolizers when standard regimes are used, and this can lead to huge differences in therapeutic effect and toxicity. There are now genotyping tests available which provide information on the individual's ability to metabolize psychotropic medication. One author provides an account of the effects of medication on her son's physical and psychological well‐being. Genotyping provided evidence for his poor metabolism of psychotropic medication, and his life is now changing as he is being very gradually weaned off this medication. This emerging field of work has implications for the way in which practitioners consider medication adherence.
Intramuscular injections: a review of best practice for mental health nurses
Authors: COCOMAN A. , MURRAY J.
Published: May 2008

This paper reviews practice in the area of intramuscular (IM) injection administration, an everyday activity for many nurses in clinical practice. The authors address administration of neuroleptic depot drugs within the adult mental health environment and examine the evidence base for this practice. A historical overview of injection practices and use of the dorsogluteal site is given, followed by more contemporary evidence on the benefits of using the ventrogluteal, deltoid and thigh sites. The authors point out that despite being a very commonplace nursing activity, there is a dearth of research‐based guidelines for nurses in this area. A quantity of published papers and nursing texts on injection sites and techniques were assessed to evaluate their quality and relevance and their overall benefit to improving clinical practice. Much of the literature available was in the form of opinion pieces without a sound research/evidence base. There appears, however, to be enough consensual evidence to form an evidence‐based clinical guideline for the administration of IM injections. The review of the available evidence, albeit at times contradictory, is presented along with a discussion of the implications for nurses.
Job satisfaction among psychiatric registered nurses in new England
Authors: SHARP T. P.
Published: May 2008

This research used Herzberg et al.'s two‐factor theory as a framework with which to examine job satisfaction in a sample of 161 registered psychiatric nurses in the states of Connecticut, Maine and Massachusetts (USA). Weiss et al.'s Minnesota Satisfaction Questionnaire short form was used to measure possible relationships between ability utilization, compensation, co‐workers, achievement and job satisfaction. Findings support Herzberg et al.'s theory, showing moderate correlations among nurses' ability utilization, achievement and job satisfaction. Mean general satisfaction of respondents was closer to satisfied than neutral; respondents indicated greatest satisfaction with ability utilization (86%) and achievement (83%); 67% were satisfied with co‐workers, and 52% with compensation. Respondents were least satisfied with compensation, with 14% indicating that they were very dissatisfied. Although compensation was an issue, it is possible that other factors, such as safety, management conflict, and balancing the needs of job and family, if addressed, may help increase job satisfaction and retention of psychiatric nursing staff.
The necessity, barriers and ways forward to meet user‐based needs for emotionally intelligent nurses
Authors: HURLEY J.
Published: May 2008

Emotional intelligence (EI) has enjoyed growing attention from researchers, educationalists and the public. Arguably, disagreement over the exact nature of EI fuelled by a low level of widely accepted empirical data has stalled its wider application into some areas of professional training. While enjoying significant popularity in areas such as business and leadership, EI remains largely absent from the curriculum of nursing. This paper argues that EI forms the very cornerstone upon which sits desirable mental health nursing abilities as identified by users and recent professional reviews. While distance education and e‐learning play an increasingly significant role in nurse education, the enhancement of EI occurs primarily through a socialization process necessitating a ‘repackaging’ of the nursing curriculum. This paper also proposes that through using service user needs and recent professional reviews as a source for learning outcomes an outline of this ‘repacking’ can be achieved.
Life events; their role in onset and relapse in psychosis, research utilizing semi‐structured interview methods: a literature review
Authors: FALLON P.
Published: May 2008

This literature review explores the findings of studies that adopted semi‐structured interviewing methods to assess the impact of life events on the course of psychotic illness. It begins by discussing the historical context and theoretical underpinnings of the use of semi‐structured approaches to measure the role and impact of life events in the onset and course of psychotic illness. The review then focuses on the main findings of the studies commencing by focusing on causality by specifically discussing the time frame from life event to relapse and whether life events have a triggering role or cumulative effect in onset. The review examines the sample populations studied and asks whether they are homogenous and comparable or heterogeneous, therefore making comparisons between studies less valid. Issues concerning the number of episodes of illness and sensitivity to relapse are explored. The review concludes that despite a general acceptance in the literature that life events have an impact on psychotic illness the findings of life events studies provide contradictory and inconclusive results and that this is at least partly attributable to the differing methodologies utilized. Continued methodological refinements may generate a ‘gold standard’ methodology that with repeated use will provide consistency in findings.
Evaluation of perceived usefulness of activity scheduling in an inpatient depression group
Authors: IQBAL S. , BASSETT M.
Published: May 2008

Recent studies have documented that inpatient care on acute psychiatric wards is ineffective. Government directives suggest that wards should initiate and provide a choice of therapeutic and recreational activities. Priority should be given to effective treatments, such as cognitive behavioural therapy. Homework tasks, such as activity scheduling (AS), form an important part of cognitive behavioural therapy for depression. To address inactivity on the wards and use more evidence‐based interventions, a quality improvement project was carried out that implemented AS in an inpatient depression group programme. Both inpatients' and staff's perception of its usefulness was evaluated. Sixteen inpatients completed the Beck Depression Inventory‐II, and a questionnaire, which was specifically designed to assess the perceived usefulness of AS. In addition, 14 nursing staff completed a similar questionnaire. Both quantitative and qualitative analyses were carried out. Results showed that all participants found AS useful. Eight inpatients had not engaged in any activity prior to being involved in AS. Most inpatients reported gaining some pleasure and satisfaction out of doing AS and experienced a positive effect on their mood and recovery. While 12 staff expressed interest in learning more about AS, 10 needed more information before carrying it out themselves, and only four had the time to do so. The perceived usefulness of AS will be discussed within the context of a psychiatric inpatient setting.
The Hypersensitive Reaction in Tobacco Leaf Tissue infiltrated with Pseudomonas pisi 4. Scanning Electron Microscope Studies on fractured Leaf Tissue
Authors: Sigee D. C. , Al‐Issa A. N.
Published: May 2008

Leaves of tobacco infiltrated with Pseudomonas pisi were fractured at various times during the course of the hypersensitive reaction to expose cell surfaces within the tissue and mesophyll cell contents. Scanning electron microscopy of cross‐fractured mesophyll cells did not reveal any gross change in internal structure during the reaction induction period (0—2 h), but breakdown of tonoplast and collapse of chloroplasts commenced at about 5 h, during the latent period. Death of the mesophyll cells was followed by condensation of cell contents, and pronounced stretching of cell walls, due to desiccation and shrinkage.Between 0—6 h after infiltration, bacteria were largely confined to cell junctions, frequently within droplets. With collapse of the host cells and release of cell fluid, numbers of bacteria increased considerably (many dividing cells), and there was a shift of bacterial distribution to the whole mesophyll cell surface. The progressive desiccation that occurred between 10—20 h prevented further bacterial increase, but numbers of bacteria remained stable. Death of bacteria commenced at about 15 h, and was accompanied by the formation of numerous surface protrusions, which detached and deposited over the whole mesophyll surface.
Mechanism of Genome Expression in a Single‐stranded RNA Virus from the Cultivated Mushroom [Agaricus bisporus (Lange) Imbach]
Authors: Tavantzis M. , Romaine C. P. , Smith S. H.
Published: May 2008

The single‐stranded RNA genome of a bacilliform virus from the common cultivated mushroom, Agaricus bisporus, was translated in an in vitro rabbit reticulocyte system. Optimal conditions for translation of mushroom bacilliform virus (MBV) RNA were 2.5 mM Mg2+, 70 mM K+, pH 7.2, and 60μg/ml RNA. Gel electrophoretic analysis showed that MBV RNA directs the synthesis of two major polypeptides of MW 77,000 and 37,000 and possibly several minor polypeptides (MW 21,000—28,000). An RNA polymerase activity could not be detected in purified virus preparations. The findings support the notion that the MBV genome functions directly as messenger for protein synthesis and further establishes the closer similarity between MBV and viruses of higher plants than mycoviruses.
Elektronenmikroskopische Untersuchungen des Gerstenmehltaus (Erysiphe graminis DC f. sp. hordei Marchal) nach Resistenzinduktion mit mikrobiellen Stoffwechselprodukten
Authors: Ebrahim‐Nesbat F. , Balder H. , Schönbeck F.
Published: May 2008

Electron microscopical studies on Mildew of Barley (Erysiphe graminis DC f. sp. hordei Marchal) after induced Resistance with Products of Microbial Metabolism

Ultrastructural studies of the infection progress of barley by Erysiphe graminis after induction of resistance with products of microbial metabolism showed that pathogen development was affected through inducer activated defence mechanisms. The formation of papillae‐like structures and an accumulation of electron dense material below the host cell wall at the penetration site appeared to be associated with reduced penetration. The haustoria were also altered in the extrahaustorial membrane and electron dense material accumulated at the cell wall of haustorial body and neck, thus apparently impairing efficient functioning and allowing only limited growth of the pathogen.
Cellulolytic Activity of Botrytis cinerea in vitro and in vivo
Authors: Verhoeff K. , Lihm J. I. , Scheffer R. J. , Surya I.
Published: May 2008

Experiments were carried out to determine whether stepwise breakdown of native cellulose is carried out by B. cinereain vitro and in vivo. Protein fractions were obtained from ungerminated conidia, from culture filtrates 24, 48 and 96 h after inoculation with conidia, and from culture filtrates of 12 day‐old cultures growing on cotton wool as the carbon source. In addition, petioles and fruits of tomato plants were inoculated and the protein fraction of the colonized tissues were tested. Using filter paper, carboxymethylcellulose and cellobiose as substrates, all fraction showed c1, glucanase and cellobiase activity respectively.
Foliar Spray of Urea and Rhizosphere Microflora of Corn (Zea mays L.)
Authors: Annapurna Y. , Rao P. Raghuveer
Published: May 2008

Foliar application of urea to corn seedlings resulted in the preferential stimulation of gram negative bacteria with consequent reduction in fungal and actinomycete flora in the rhizosphere. The significance of this finding is briefly discussed.
Association of Tobacco Ringspot Virus with a Union Incompatibility of Apple
Authors: Lana Allan Femi , Peterson J. F. , Rouselle G. L. , Vrain T. C.
Published: May 2008

A virus‐like disease of apple was observed for the first time in Canada in 1974 in a three year old planting. The disease was characterised by stem pitting, necrosis and breaking or separation of scion/rootstock at the graft union. Foliage was sparse and leaves were chlorotic and diffusely mottled. Using both frozen and freshly harvested leaves of infected apple trees from rootstock suckers as inoculum, a virus was transmitted to herbaceous indicator hosts. Based on host range symptoms, serology and electron microscopy, this virus was identified as tobacco ringspot virus. Initial counts of nematodes in the rhizophere of apple trees affected with union necrosis showed high densities of Xiphinema americanum Cobb., a known vector of nepoviruses. Reports of similar symptoms have indicated that the disease, apple union necrosis and decline was associated with the recovery of tobacco ringspot virus from infected rootstocks. This is the first report associating a union incompatibility condition of apple and tobacco ringspot virus.
Some Properties of Cucumber Fruit Streak Virus
Authors: Gallitelli D. , Vovlas C. , Avgelis A.
Published: May 2008

An isometric virus c. 30 nm in diameter with a single RNA species (mol.wt 1.45 × 106) isolated from cucumber plants from the island of Crete (Greece) is described under the name of cucumber fruit streak virus (CFSV). The most evident symptom on naturally infected plants consisted of longitudinal chlorotic streak of the fruits. In glasshouse, the virus was soil‐transmitted to C. sativus, and, mechanically, to a wide range of herbaceous hosts, most of which were infected only locally.

Purified virus preparations sedimented as a single component with sedimentation coefficient of 132S. At equilibrium these preparations were homogeneous in CsCl gradients but formed two bands in Cs2SO4 gradients. Virus particles were stabilized by forces involving divalent cations, pH‐dependent bonds and salt links between protein and RNA. Although some of the properties of CFSV are similar to those of other small spherical viruses with single RNA species there are differences which do not allow for the assignment of the virus to any of established taxonomic group of plant viruses.
Recovery of Pseudocercosporella herpotrichoides Spores from Rain‐Splash Samples
Authors: Fitt B. D. L. , Bainbridge A.
Published: May 2008

Methods for recovery of P. herpotrichoides spores from rain‐splash were tested, initially with pure spore suspensions and then with field samples. Provided surfactant was added and samples were processed immediately, centrifugation gave good recovery or spores from field samples which contained few soil particles. Foam‐flotation, glycerol and sucrose methods for separation of spores from soil particles were not satisfactory for P. herpotrichoides spores. A paraffin oil method proved to be the most reliable because it gave good recovery of P. herpotrichoides spores from field samples containing many soil particles.
Plant Viruses Affecting Tomatoes in Jordan. Identification and Prevalence
Authors: Al‐Musa A. , Mansour A.
Published: May 2008

A survey was conducted during the period 1979–1982 to identify viruses affecting tomatoes in the Jordan Valley. Results indicated the rare occurrence of mosaic diseases caused by tobacco mosaic virus, cucumber mosaic virus, or potato virus Y. However, tomato yellow leaf curl virus was predominant.
Life Cycle of Botryodiplodia theobromae, a Soft Rot Pathogen of Yam
Authors: Ogundana S. K.
Published: May 2008

Botryodiplodia theobromae Pat. forms chlamydospores and specialised hyphae in diseased yam tissues in which condition it tides over unfavourable periods. With favourable conditions the chlamydospores germinate and the specialised hyphae formed serve as sources of infection to new hosts and infect through wounds. Germination tubes infect by means of terminal appressoria, and nutrition within the host is effected by production of haustoria.
Fungitoxicity of Some Higher Plants with Special Reference to the Synergistic Activity Amongst some Volatile Fungitoxicants
Authors: Pandey D. K. , Chandra H. , Tripathi N. N. , Dixit S. N.
Published: May 2008

During screening of the leaves of 25 plant species for their volatile toxicity against the test pathogen Fusarium lateritium f.sp.cajani, Aegle marmelos (Ae), Citrus aurantifolia (Ci) and Mentha arvensis var. piperascens (Me) exhibited strong toxicity inhibiting the mycelial growth completely. The active volatile constituents from each plant were isolated in the form of essential oil and the fungitoxicity of each oil was tested separately. The Aegle oil was found fungistatic while Citrus and Mentha oils were fungicidal in nature. Three oil combination (1:1 v/v) viz., Ae‐Ci, Ae‐Me and Ci‐Me were made and their fungitoxicity was tested. The oil combinations were found to be more fungitosic than the individual oils, which were fungistatic in nature. The Ci‐Me combination exhibited a broad fungitoxic spectrum while the other two Ae‐Ci and Ae‐Me possessed a narrow range of toxicity. The oils were found to have no toxic effect on seed germination, seedling growth (root and shoot length), and general morphology of the host plant(Cajanus cajan).
A Role for Pectinase and Protease Inhibitors in Fungal Rot Development in Tomato Fruits
Authors: Brown A. E. , Adikaram N. K. B.
Published: May 2008

B. cinerea and C. atramentarium rotted wound‐inoculated green tomato fruits and wounded or intact ripe fruits while G. cingulata developed rots only in ripe fruits. Pectic en‐zymes were extracted from the fruit tissue rotted by B. cinerea and C. atramentarium but no pectic enzymes attributable to the fungus were detected in ripe fruits rotted by G. cingulata. G. cingulata produced endo‐PG and endo‐PL in vitro, C. atramentarium produced endo‐PL in vitro and in vivo and B. cinerea produced exo‐PG in vitro and in green fruits but endo‐PG and endo‐PL in ripe fruits. Well ripened tomato fruits contained high levels of endogenous PG. All three fungi produced proteolytic enzymes in vitro and in vivo. Proteases produced by G. cingulata and C. atramentarium had optimum activity at pH 9 to 10 and were not trypsin‐like or chymotrypsin‐like in nature. Protease produced by B. cinerea had optimum activity at pH 7 and showed both trypsin and chymotrypsin‐like activity.

Proteins extracted from the cell walls of tomato fruits inhibited both the endo‐PG and endo‐PL produced by G. cingulata and the endo‐PL produced by B. cinerea but did not in‐hibit the activity of PGs produced by B. cinerea, the endo‐PL produced by C. atramentarium or the endogenous PG from tomato fruits.

The cell wall proteins also contained trypsin and chymotrypsin inhibitor activity which inhibited 70 % of the activity of the protease produced by B. cinerea, but had little effect on the proteases produced by G. cingulata, C. atramentarium or the tomato endogenous protease.

Enzymes produced in vitro by G. cingulata macerated green tomato tissue more slowly than enzymes produced in vitro by C. atramentarium and B. cinerea and the rate of mation was further reduced in the presence of added cell wall proteins. Excess inhibitor of the little effect on the rate of maceration by the enzymes produced by C. atramentarium of the cinerea.
Membrane Permeability of Conidia of Bipolaris oryzae
Authors: Nanda H. P. , Gangopadhyay S.
Published: May 2008

Germinability of the conidia of B. oryzae, after an efflux of substances — both electrolytes and non‐electrolytes — was tested in sterilized solutions of plasmolytica and osmotica, ranging from molarity to 10−12 M. Maximum percent germination was recorded at 10−8 M concentration regardless of the exogenous supplement in the order KCl >D‐glucose >Mannitol >NaCl. Germination was very poor or non‐existent in other, higher or lower molarities tested except at 10−7 M wíth c. 50% germination. In nature the conidia, though nutrient independent, are subject to leaching and likely to lose viability; hence the possible role of the proper osmoticum, basing on the observed fact, in maintenance of membrane equilibrium and germinability of the leached conidia has been discussed.
A Messenger RNA for Tobacco Mosaic Virus Coat Protein in Infected Tobacco Mesophyll Protoplasts
Authors: Ogawa M. , Sakai F. , Takebe I.
Published: May 2008

The low molecular weight tobacco mosaic virus (TMV)‐specific RNA component (LMC) was demonstrated in tobacco mesophyll protoplasts by polyacrylamide gel electrophoresis of 14C‐uridine‐labelled RNA from infected protoplasts.

Free and membrane‐bound polysomes were isolated from infected protoplasts, and RNA extracted from them was analyzed. TMV‐specific RNA species including full‐length viral RNA, its replicative intermediate, and LMC were found in both free and membrane‐bound polysomes, but were present in free polysomes in much larger amounts. In particular, as much as 37 % of total LMC in protoplasts was found in free polysomes. Fractionation of polysomes by sedimentation in sucrose gradients showed that LMC is associated with small‐sized polysomes (mono‐ to tetrasomes). Polysomes of this size class produced viral coat protein in a cell‐free protein synthesizing system from rabbit reticulocytes. On the other hand, full‐length TMV‐RNA was associated predominantly with larger polysomes which produced in the cell‐free system TMV‐specific high molecular weight polypeptides but no coat protein. These results indicated that LMC, a subgenomic RNA of TMV, in fact functions in vivo as messenger RNA for viral coat protein, as has been postulated on the basis of in vitro studies.
Studies on the Host Range of the Hyperparasite Aphanocladium album
Authors: Koç N. K. , Défago G.
Published: May 2008

The uredospores of the 14 rust species tested and an Ascochyta, sp. were heavily parasitized by A. album. The teliospores of 3 Ustilaginales species were slightly parasitized. Some other important plant parasites were inhibited at distance, some others did not show any damage.
The Effects of Aspirin and Polyacrylic Acid on the Multiplication and Spread of TMV in Different Cultivars of Tobacco with and without the N‐gene
Authors: White R. F. , Antoniw J. F. , Carr J. P. , Woods R. D.
Published: May 2008

Aspirin treatment of leaves of Nicotiana tabacum cv. Samsun at 20°C induced PR‐proteins and reduced the amount of tobacco mosaic virus (TMV) accumulated 7 days after inoculation. However, at 32°C both the amount of PR‐proteins induced and the reduction of TMV accumulated were less. Polyacrylic acid did not induce PR‐proteins, and caused little or no reduction in the amount of TMV accumulated at 20°C. In cv. Samsun NN at 32°C. aspirin induced the PR‐proteins and reduced the spread of TMV to surrounding tissue as treasured by the size of lesions produced on subsequent transfer to 20°C. Polyacrylic acid did not induce PR‐proteins in Samsun NN and had no effect on the spread of TMV. In cv. Xanthi‐ne, at 32°C aspirin and polyacrylic acid induced PR‐proteins and reduced the spread of TMV. At 35°C, polyacrylic acid induced little or no PR‐proteins and did not affect the spread of TMV.
Physical and Chemical Properties of Potato Aucuba Mosaic Virus and its Coat Protein
Authors: Artyukova E. V. , Krylov A. V.
Published: May 2008

Some properties of potato aucuba mosaic virus (PAMV) were studied. PAMV virions have a buoyant density in CsCl of 1.315 g/cm3 and RNA content of 5.06 ± 0.1 %.

Limited proteolysis of the PAMV capsid protein at N‐termini has been found in the process of virus isolation and storage. The race of protein degradation was considerably decreased by the presence of phenylmethyl sulphonylfluoride — a protease inhibitor — in resuspending buffer. Molecular weight estimates were 27,480 ± 319 for native PAMV protein and 24,113 ± 129 and 21,634 ± 124 for main breakdown products. Amino acid composition of the native PAMV protein seems to be very similar to that of native PVX protein and differs only in threonine, leucine, histidine, tyrosine and methyonine.

All studied properties of PAMV and its protein confirm the belonging of PAMV to the potexvirus group.
Observation of Potato Virus X in Tobacco Mosaic Virus (TMV)‐ Induced Local Lesions and Surrounding Zones in Leaves of Datura stramonium L. in Mixed Infection
Authors: Reunov A. V. , Lega S. N.
Published: May 2008

In mixed infection by Tobacco Mosaic Virus (TMV) and Potato Virus X (PVX) of leaves of Datura stramonium L., PVX particles were observed in the developing local lesions in both the central part and on the periphery, in addition to TMV. PVX virions were found either separately or together with TMV. Sometimes in local lesions mainly in their periphery, PVX‐specific laminar inclusion components were observed and, in certain cases, cylindrical bodies about 120—140 nm in diameter.

In 2 mm surrounding zones from the edge of the lesions, TMV particles were not observed. However, in the majority of cells of these zones, PVX intensively accumulated, often forming large masses. In some cases, we observed parts of cells with relatively small amounts of dispersed PVX particles, associated with laminar inclusion bodies. In cell areas with large accumulations of PVX, laminar inclusions were not found.
Wissadula Proliferation in Jamaica II. Psyllid transmission and antibiotic therapy
Authors: Dabek A. J.
Published: May 2008

Field symptoms of Wissadula proliferation (WP) in Jamaica were reproduced on W. periplocifolia (L.) C. Presl. ex Thwaites test plants, using field‐collected or laboratory reared and infected Paracarsidara concolor Crawford. This psyllid naturally is associated with W. periplocifolia in the field. Diseased plants contained phloem‐restricted prokaryotes, most of which resembled the phloem‐restricted rickettsialike organisms (RLO) known to be associated with a small group of plant diseases. They were bound by a “cell wall” composed of a double unit membrane separated by an electron‐lucent layer. A small proportion of the prokaryotes, which were bound by only one recognizable unit membrane and were ill‐defined at the periphery, were difficult to distinguish from mycoplasmalike organisms (MLO). Penicillin, applied as a soil drench of 200—400 %mUg/ml caused remission of symptoms of the psyllid‐infected test plants 6—17 days after first effective application, with the concomitant disappearance of all of the structures in the resulting new growth. Since MLO are not known to be penicillin‐sensitive, it is proposed that the “MLO” were in fact, poorly preserved RLO and it is suggested that RLO may be the aetiological agent of WP. Achromycin also caused symptom remission in WP at a soil drench of 100—400 %mUg/ml, but was generally slightly slower‐acting than penicillin, eliciting a response in 12—23 days. Both antibiotics could produce lengthy remissions; neither seemed curative since two penicillin‐ and two achromycin‐treated plants redeveloped symptoms after cessation of treatment. WP was not transmitted by two cicadellids, Protalebra maculata Baker and Scaphytopius fuliginosus Osborn. P. concolor did not transmit disease to test plants of Abutilon hulseanum (Torr. & A. Gray) Torr, ex. Chapm. which was affected by a proliferation disease (Abutilon proliferation), symptomatologically similar to, and which occurred in the same locations, as WP. WP and AP thus may be aetiologically distinct. The putative RLO aetiology of WP provides evidence against Wissadula being an alternate host of the MLO‐associated coconut lethal yellowing (CLY) disease in Jamaica, a fact reinforced by negative psyllid transmission tests to CLY‐susceptible palms. The results for WP are discussed in relation to other diseases possibly caused by phloem‐restricted RLO.
The Association of Brome Mosaic Virus and Wheat Rusts.
Authors: Erasmus D. S. , Rybicki E. P. , Von Wechmar M. B.
Published: May 2008

Evidence is presented in support of transmission of brome mosaic virus by uredospores of wheat stem rust (Puccinia graminis f. sp. tritici). The presence of BMV associated with uredospores is shown by the use of sensitive serological assays such as, fluorescent antibody binding studies, enzyme‐linked immunosorbent assay and immunosorbent electron microscopy. The virus is shown to be carried externally on the uredospores. The nature of the association of the virus with uredospores and its relation to the mode of carriage and transmission of the virus by the uredospores, as well as the importance of this association in the epidemiology of the virus is discussed.