SENSITIVITY OF DAUDI CELLS TO TUMOR NECROSIS FACTOR ALPHA: EARLY CHANGES IN POLYPHOSPHOINOSITIDE METABOLISM

The effects of recombinant Tumor Necrosis Factor α (r-TNF α) on polyphosphoinositide metabolism were examined in a Burkitt Lymphoma cell line (Daudi cells). After 1h of in vitro treatment with r-TNF α, the incorporation of³²Pi into phosphatidylinositol 4,5-phosphate (PtdInsP₂), phosphatidylinositol 4-phosphate (PtdInsP) and phosphatidylinositol (PtdIns) was reduced compared with controls, confirming previous findings observed in other cell lines of a specific PtdIns breakdown following r-TNF α treatment. The novelty of this study is therefore the demonstration of early changes in polyphosphoinositide metabolism during the antiproliferative response elicited by this cytokine in Daudi cells.     

Study of 2D ion chamber array for angular response and QA of dynamic MLC and pretreatment IMRT plans

AimTo study of 2 Dimensional ion chamber array for angular response and its utility for quality assurance of dynamic multileaf collimator and pretreatment intensity modulated radiotherapy plans.Materials and MethodsThe MLC QA test patterns and IMRT plans were executed on 2D ion chamber array having 1020 vented pixel ionization chambers. The dynamic MLC QA test patterns were chair test, x–wedge, pyramid, open swipe field, garden fence and picket fence. Performance of Dynamic wedges was compared with physical wedges. For IMRT verification, five patients with localized prostate carcinoma were planned using dynamic IMRT technique. Angular response of MatriXX was measured by exposing the system from different gantry angles.ResultsDynamic MLC QA tests such as chair, x-wedge, pyramid, and open swipe field were successfully verified. MatriXX was not able to recognize the bar pattern of picket test and garden fence test. The response of MatriXX gradually decreases from 0° to 180° angles and it was 7.7% less at 180° angle. The dynamic wedge profiles were matching with corresponding physical wedge profiles. For pretreatment IMRT QA, the average dose difference between planned and measured dose was 1.26% with standard deviation of 1.06.ConclusionI'mRT MatriXX can be used for routine dynamic MLC and IMRT pretreatment QA but care should be taken while taking measurements in penumbra region because of its limited spatial resolution.     

Syncytes during male meiosis resulting in 2n pollen grain formation in Lindelofia longiflora var.falconeri

Lindelofia longiflora (Royle ex Benth.) Baill.var.falconeri (Cl.) Brand (Family:Boraginaceae) is investigated cytologically (n =12) for the first time from the cold deserts of Pangi Valley,Chamba District (Himachal Pradesh) in India.We report the formation of syncytes and 2n pollen grains in the species.During meiosis,the majority of the pollen mother cells (PMCs) exhibited 12 bivalents,equal segregation of chromosomes during anaphases,regular tetrads,and normal-sized pollen grain formation.Occasionally,two proximate PMCs fused during the early stages ofprophase-I and resulted in the formation of syncytes.The frequency of syncytes in the accession is rather low,at 25 out of 1866 (1.33％).Such syncyte PMCs are detectable during meiosis due to their larger size compared to typical PMCs.The syncytes or polyploid cells showed normal 24 bivalents and depicted perfectly regular meiotic course.But the products of such PMCs yield 2n or larger sized pollen grains that are almost double the size of typical normal or n pollen grains.The origin of syncytes as a consequence of the fusion of meiocytes during the early stages of meiosis-I could be attributed to low temperature stress conditions prevailing in the Pangi Valley,where temperature during May and June dip to below freezing,the time the plants enters the reproductive/flowering bud stage.It is possible that such apparently fertile 2n pollen grains originating from syncytes might play a role in the origin of intraspecific polyploids in the species.     

Syncytes during male meiosis resulting in 2n pollen grain formation in Lindelofia longiflora var. falconeri

Abstract Lindelofia longiflora (Royle ex Benth.) Baill. var. falconeri (Cl.) Brand (Family: Boraginaceae) is investigated cytologically (n= 12) for the first time from the cold deserts of Pangi Valley, Chamba District (Himachal Pradesh) in India. We report the formation of syncytes and 2n pollen grains in the species. During meiosis, the majority of the pollen mother cells (PMCs) exhibited 12 bivalents, equal segregation of chromosomes during anaphases, regular tetrads, and normal‐sized pollen grain formation. Occasionally, two proximate PMCs fused during the early stages of prophase‐I and resulted in the formation of syncytes. The frequency of syncytes in the accession is rather low, at 25 out of 1866 (1.33%). Such syncyte PMCs are detectable during meiosis due to their larger size compared to typical PMCs. The syncytes or polyploid cells showed normal 24 bivalents and depicted perfectly regular meiotic course. But the products of such PMCs yield 2n or larger sized pollen grains that are almost double the size of typical normal or n pollen grains. The origin of syncytes as a consequence of the fusion of meiocytes during the early stages of meiosis‐I could be attributed to low temperature stress conditions prevailing in the Pangi Valley, where temperature during May and June dip to below freezing, the time the plants enters the reproductive/flowering bud stage. It is possible that such apparently fertile 2n pollen grains originating from syncytes might play a role in the origin of intraspecific polyploids in the species.     

Effect of high external NaCl concentration on ion transport within the shoot of Lupinus albus. II. Ions in phloem sap

Abstract. Phloem sap was collected from petioles of growing and fully expanded leaves of lupins exposed to 0–150 mol m⁻³ [NaCl]_ext, for various periods of time. Sap bled from growing leaves only after the turgor of the shoot was raised by applying pneumatic pressure to the root. Increased pressure was also needed to obtain sap from fully expanded leaves of plants at high [NaCl]_ext. Exposure to NaCl caused a rapid rise in the Na⁺ concentration in phloem sap to high levels. The Na⁺ concentration reached 20 mol m⁻³ within a day of exposure and reached a plateau of about 60 mol m⁻³ in plants at 50–150 mol m⁻³ [NaCl]_ext, after a week. There was a slower, smaller increase in the Cl⁻ concentration. K⁺ concentrations in phloem sap were not affected by [NaCl]_ext. Cl⁻ concentrations in phloem sap collected from growing leaves were similar to those from old leaves while Na⁺ concentrations were somewhat increased, suggesting that there was no reduction in the salt content of the phloem sap while it flowed within the shoot to the apex. Calculations of ion fluxes in xylem and phloem sap indicated that Na⁺ and Cl⁻ fluxes in the phloem from leaves of plants at high NaCl could be equal to those in the xylem. This prediction was borne out by observations that Na⁺ and Cl⁻ concentrations in recently expanded leaves remained constant.     

The Role of the Stem in the Partitioning of Na+ and K+ in Salt-Treated Barley

Hordeum vulgare cv. California Mariout was grown for 50 d insand culture at 100 mol m^–3 NaCl. Xylem sap was collectedthrough incisions at the base of individual leaves along thestem axis by applying pressure to the root system. K⁺ concentrationsin the xylem sap reaching individual leaves increased towardsthe apex, while concentrations of Na⁺, NO₃^–, and Cl^–declined. Phloem exudate was obtained by collecting into Li₂EDTAfrom the base of excised leaves. K/Na ratios of phloem exudatesincreased from older to younger leaves. K/Na ratios in xylem sap and phloem exudate were combined withchanges in ion content between two harvests (38 and 45 d aftergermination) and the direction of phloem export from individualleaves, to construct an empirical model of K⁺ and Na⁺ net flowswithin the xylem and phloem of the whole plant. This model indicatesthat in old leaves, phloem export of K⁺ greatly exceeded xylemimport. In contrast, Na⁺ export was small compared to importand Na⁺ once imported was retained within the leaf. The direction of export strongly depended on leaf age. Old,basal leaves preferentially supplied the root, and most of theK⁺ retranslocated to the roots was transferred to the xylemand subsequently became available to the shoot. Upper leavesexported to the apex. Young organs were supplied by xylem andphloem, with the xylem preferentially delivering Na⁺ , and thephloem most of the K⁺ . For the young ear, which was still coveredby the sheath of the flag leaf, our calculation predicts phloemimport of ions to such an extent that the surplus must havebeen removed by an outward flow in the xylem. Within the culm,indications for specific transfers of K⁺ and Na⁺ between xylemand phloem and release or absorption of these ions by the tissuewere obtained. The sum of these processes in stem internodes and leaves ledto a non-uniform distribution of Na⁺ and K⁺ within the shoot,Na⁺ being retained in old leaves and basal stem internodes,and K⁺ being available for growth and expansion of young tissues. Key words: Hordeum vulgare L., K⁺, Na⁺, stem, salt stress     

Fine needle aspiration (FNA) cytology of extra-adrenal paragangliomas

Fine needle aspiration (FNA) cytology of extra-adrenal paragangliomas We studied nine histologically proved cases of extra-adrenal paragangliomas. Of these, eight cases were correctly diagnosed preoperatively by FNA cytology. Salient cytological features included clusters and discretely scattered cells, with occasional acinar configuration. The cells showed moderate to abundant slightly basophilic cytoplasm with ill-defined margins and round to oval nuclei with mild to marked nuclear pleomorphism. Fine reddish intracytoplasmic granules were also noted (six cases). Cytological features along with clinical data are quite diagnostic of paragangliomas. A correct preoperative cytological diagnosis helps to prevent undue surgical complications. Cytologie par ponction aspiration à l'aiguille fine des paragangliomes extra-surrénaliens Nous avons étudié 9 cas de paragangliomes extra-surrénaliens histologiquement prouvés. Huit cas sur 9 ont été correctement diagnostiqués, à titre pré-opératoire, par cytologie par ponction aspiration à l'aiguille fine. Les caractéristiques cytologiques principales sont la présence d'amas, une dispersion cellulaire modérée et d'occasionnelles formations acineuses. Les cellules comportent un cytoplasme légèrement basophile, moyennement à très abondant, avec des limites mal définies ainsi qu'un noyau rond ou ovale, dont le pléomorphisme nucléaire est modéré ou plus nettement marqué. Le présence de fines granulations rougeâtres intra-cytoplasmiques a également été notée (6 cas). Ces caractères cytologiques, associés aux données cliniques, permettent pratiquement le diagnostic des paragangliomes. Un diagnostic cytologique pré-opératoire correct favorise la prévention des complications chirurgicales indésirables. FNP extraadrenaler Paragangliome Neun histologisch gesicherte Fälle extraadrenaler Paragangliome werden vorgestellt. Präoperativ waren 8 der Fälle zytologisch durch FNP richtig diagnostiziert worden. Charakteristisch waren Einzelzellen und z.T. azinäre Verbände. Die Zellen zeigten mässig bis reichlich, leicht basophiles, unscharf begrenztes Zytoplasma und rund-ovale Kerne mit leichter bis ausgeprägter Pleomorphie. In 6 Fällen lagen feine, rote Granula im Zytoplasma vor. Das zytologische Bild in Zusammenschau mit den klinischen Daten erlaubt eine sichere Diagnose. Auf diese Weise können die operativen Risiken vermindert werden.     

Host range and properties of artichoke yellow ringspot virus

The biological, serological and physico-chemical properties of one isolate of artichoke yellow ringspot virus (AYRV) from Greece and another from Italy were compared. Both isolates infected 56 herbaceous species and there were few differences between them in the symptoms they caused. During purification they behaved identically and both tended to aggregate. Virus particles were isometric and measured c. 30 nm in diameter. In CsCl, virus sedimented as mixed aggregates of empty and full particles with buoyant densities varying from 1.20–1.30 g/ml and from 1.40–1.53 g/ml, respectively. The coat protein of AYRV contains a single polypeptide of mol. wt 53000 and the genome consists of two species of single-stranded RNA with mol. wts 2.17 × 10⁶ (RNA-1) and 1.85 × 10⁶ (RNA-2) daltons, estimated under denaturing conditions. The two virus isolates are serologically very closely related but are unrelated to 28 other plant viruses with isometric particles. The characteristics of AYRV suggest that it is a possible member of the nepovirus group.     

Life‐history consequences and disease resistance of western tent caterpillars in response to localised,herbivore‐induced changes in alder leaf quality

1. Plants can respond to herbivore damage with phenotypically plastic changes in quality that negatively affect herbivores and prevent subsequent attack – induced defences. 2. The present study tested whether trees respond to herbivory with localised induction, and whether life‐history traits and disease resistance of an insect herbivore are altered on induced branches of the trees. 3. The influences of localised, within‐branch, herbivore‐induced changes in red alder trees (Alnus rubra Bong.) on fitness characteristics of western tent caterpillars (Malacosoma californicum pluviale Dyar) were evaluated. In the field, randomly selected branches of trees were infested with tent caterpillar larvae and the adjacent branches were maintained as non‐infested controls. In the laboratory, larvae were fed leaves from either induced or non‐induced branches through to adult emergence. A second cohort of larvae was challenged with a viral pathogen to compare their disease susceptibility on induced versus non‐induced foliage. 4. Herbivore‐induced, localised responses of damaged branches reduced leaf quality for growth and the fecundity of female western tent caterpillars, but not that of males. Larvae fed induced leaves had a higher survival overall and a reduced mortality due to unidentified non‐viral pathogens than did their counterparts on non‐induced leaves. However, there was no influence of leaf quality on baculovirus‐induced mortality. 5. These findings suggest that localised induced changes in leaf quality could potentially influence populations of tent caterpillars in contradictory ways by reducing their growth rate and fecundity to a modest degree, while improving their survival and resistance to unidentified non‐viral pathogens to a larger extent.