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Multinucleate Cells (multinucleate + cell)
Selected AbstractsNovel functions of ribosomal protein S6 in growth and differentiation of Dictyostelium cellsDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 6 2009Kazutaka Ishii We have previously shown that in Dictyostelium cells a 32 kDa protein is rapidly and completely dephosphorylated in response to starvation that is essential for the initiation of differentiation (Akiyama & Maeda 1992). In the present work, this phosphoprotein was identified as a homologue (Dd-RPS6) of ribosomal protein S6 (RPS6) that is an essential member for protein synthesis. As expected, Dd-RPS6 seems to be absolutely required for cell survival, because we failed to obtain antisense-RNA mediated cells as well as Dd-rps6 -null cells by homologous recombination in spite of many trials. In many kinds of cell lines, RPS6 is known to be located in the nucleus and cytosol, but Dd-RPS6 is predominantly located in the cell cortex with cytoskeletons, and in the contractile ring of just-dividing cells. In this connection, the overexpression of Dd-RPS6 greatly impairs cytokinesis during axenic shake-cultures in growth medium, resulting in the formation of multinucleate cells. Much severe impairment of cytokinesis was observed when Dd-RPS6-overexpressing cells (Dd-RPS6OE cells) were incubated on a living Escherichia coli lawn. The initiation of differentiation triggered by starvation was also delayed in Dd-RPS6OE cells. In addition, Dd-RPS6OE cells exhibit defective differentiation into prespore cells and spores during late development. Thus, it is likely that the proper expression of Dd-RPS6 may be of importance for the normal progression of late differentiation as well as for the initiation of differentiation. [source] Studies on anastomosis groups of Rhizoctonia solani isolates causing disease in two forest nurseries in PolandFOREST PATHOLOGY, Issue 2 2006S. St, pniewska-Jarosz Summary Thirty-eight isolates of Rhizoctonia spp. were isolated from Scots pine (Pinus sylvestris) seedlings with damping-off symptoms, originating from two forest nurseries in central-west Poland (Wronczyn and Jarocin) and from diseased seedlings grown in soil from Wronczyn nursery. Majority of these isolates (79%) had multinucleate cells and were identified as Rhizoctonia solani. The remaining isolates were recognized as binucleate Rhizoctonia spp. R. solani isolates were characterized using hyphal anastomosis and were divided into five anastomosis groups (AG). The most prevalent was AG5 (37% of isolates), followed by AG2-1 (30%) and 27% of the isolates were identified as AG4. Groups AG1-IB and AG2-2 were only represented by single isolates. The virulence recorded as mortality (in percentage) was comparatively high for binucleate and multinucleate isolates of Rhizoctonia spp. Sequence analysis of the polymerase chain reaction (PCR)-amplified internal transcribed spacer (ITS) rDNA region was used for phylogenetic analysis. The dendrogram showed that isolates were distinctly separated based on their AG types and there was no relationship between pathogenicity on Scots pine seedlings and the AG to which the isolates belong to. The results are discussed with respect to pathogenic potential of the various AG groups. Résumé Trente-huit isolats de Rhizoctonia spp. ont été isolés de semis de Pin sylvestre (Pinus sylvestris) présentant des symptômes de fonte, dans deux pépinières forestières du Centre-Ouest de la Pologne (Wronczyn and Jarocin) et de semis malades élevés dans du sol provenant de la pépinière de Wronczyn. La majorité de ces isolats (79%) ont des cellules multi-nucléées et ont été identifiés comme des Rhizoctonia solani. Le reste des isolats ont été reconnus comme des Rhizoctonia spp. binucléés. Les isolats de R. solani ont été caractérisés en utilisant l'anastomose d'hyphes et répartis dans cinq groupes d'anastomoses (AG). Le plus important est le groupe AG5 (37% des isolats), suivi par AG2-1 (30%) et AG4 (27%). Les groupes AG1-IB et AG2-2 sont représentés chacun par seulement un isolat. La virulence, estimée par le pourcentage de mortalité, est relativement forte pour les isolats binucléés et multinucléés de Rhizoctonia spp. L'analyse des séquences de la région ITS de l'ADNr amplifiées par PCR a été utilisée pour l'analyse phylogénétique. Le dendrogramme montre que les isolats sont séparés selon leur groupe d'anastomose mais il n'y a pas de relation entre le groupe d'anastomose et la virulence sur semis de Pin sylvestre. Les résultats sont discutés dans la perspective du pouvoir pathogène des différents groupes d'anastomoses. Zusammenfassung Von Kiefernsämlingen (Pinus sylvestris) mit Umfallkrankheit, die aus zwei Forstbaumschulen in Zentral-Westpolen stammten (Wronczyn und Jarocin) und aus erkrankten Sämlingen, die in Bodenproben aus der Baumschule Wronczyn kultiviert worden waren, wurden 38 Stämme von Rhizoctonia spp. isoliert. Die meisten dieser Isolate (79%) hatten vielkernige Zellen und wurden als R. solani identifiziert. Die restlichen Isolate waren zweikernige Rhizoctonia spp. Die Isolate von R. solani wurden durch Anastomosierungstests charakterisiert und fünf Anastomosierungsgruppen zugeordnet. Die häufigste Gruppe war AG5 (37% der Isolate), gefolgt von AG2-1 (30%) und AG4 (27%). Die Gruppe AG1-IB und AG2-2 waren nur durch einzelne Isolate vertreten. Die Virulenz (gemessen als % Mortalität) war sowohl für zweikernige als auch für vielkernige Isolate vergleichsweise hoch. Mit den Sequenzen der PCR-amplifizierten ITS-rDNA-Region wurde eine phylogenetische Analyse durchgeführt. Das Dendrogramm zeigte, dass die Isolate aufgrund ihrer Zugehörigkeit zu den Anastomosierungsgruppen deutlich voneinander getrennt waren, und es bestand keine Beziehung zwischen ihrer Virulenz gegenüber Kiefernsämlingen und der Gruppenzugehörigkeit. Die Befunde werden im Hinblick auf das pathogene Potential der verschiedenen Anastomosierungsgruppen diskutiert. [source] Pyoderma gangrenosum of the scalp treated with cyclosporine AINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 12 2002Pasquale Patrone MD A 56-year-old woman presented with an ulcer, with a depth of 9 mm, on the vertex and frontal parietal regions of the scalp. The lesion had a round shape (diameter, 7 cm), with clear-cut margins and vertical borders sinking vertically to a bottom that was entirely covered with purulent fibrinous yellowish matter and greenish colored necrotic tissue. Other numerous small roundish ulcers were present next to the large ulcer. These had irregular margins with a yellowish fibrinous bottom (Fig. 1). The patient reported the appearance of two small ulcers on the left and on the right frontal parietal regions about 1 year earlier. These had been treated locally with antimicrobials and antiseptics with no result. During the 2 months prior to our evaluation, a few small round-shaped ulcers had appeared on the scalp. These had progressively increased in size and number. Figure Figure 1 . Large ulcer with clear-cut margins, covered by purulent fibrinous matter, and other small roundish ulcers The patient had been an insulin-dependent diabetic for 23 years. Hematochemical examinations showed no significant alterations, except for a rise in glycemia. Urine examination gave normal results. Carcinoembryonic antigen and lymphocytic phenotyping indices were normal. Echographic, endoscopic, and radiocontrast studies of the abdomen did not reveal the presence of lesions either in the gastrointestinal tract or in other organs. Samples of ulcerous tissue were collected from the scalp to perform histologic and microbiologic analysis in search of fungi and bacteria. This last examination revealed the presence of Staphylococcus aureus and Candida parapsylosis. Direct search for mycobacteria was negative. Histology indicated the presence of dermal granulomatous inflammation with giant multinucleate cells, associated with large zones of suppuration and colliquative necrosis. While waiting to complete the diagnostic course, topical antiseptic, antimicrobial, and fibrinolytic therapy was administered; subsequently, as this did not lead to any improvement, systemic treatment with cyclosporine A (5 mg/kg/day) was started. Rapid improvement of the clinical picture occurred. The ulcers appeared cleaner from the first 2 weeks of treatment, radial growth stopped, and the margins were slightly more superficial. The patient continued with immunomodulating therapy at home over a period of 7 months. The dose was progressively reduced until, over a period of about 3 months, complete re-epithelialization of the lesion, with subsequent partial regrowth of the hair, was obtained (Figs 2 and 3). No relapses were observed 1 year after treatment was suspended. Figure 2. Partial re-epithelialization of the lesion with partial regrowth of the hair Figure 3. Scar and hair regrowth [source] Longitudinal erythronychia with distal subungual keratosis: onychopapilloma of the nail bed and Bowen's diseaseBRITISH JOURNAL OF DERMATOLOGY, Issue 1 2000R. Baran We biopsied longitudinal erythronychia in 16 subjects, and found an onychopapilloma in 14 cases and Bowen's disease in the remaining two. Shared clinical features in addition to erythronychia (or sometimes an interrupted line made up of splinter haemorrhages) were typically a longitudinal marked ridge of the nail bed expanded at the distal nail bed as subungual keratosis, and associated localized onycholysis. The presentation of Bowen's disease in this pattern has not been previously reported. In all cases of onychopapilloma of the nail bed, acanthosis and papillomatosis were evident, and were associated with a keratogenous zone identical to the nail matrix. In addition, we found multinucleate giant cells in two onychopapillomas. We have therefore suggested that the term ,localized, distal, subungual keratosis with multinucleate cells' should be replaced by ,onychopapilloma' (nail-producing papilloma). [source] | |||||||||||||