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Round Shape (round + shape)
Selected AbstractsIn vitro differentiation of lineage-negative bone marrow cells into microglia-like cellsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2010Daisuke Noto Abstract Microglia are believed to be the only resident immune cells in the CNS, originating from hematopoietic-derived myeloid cells and invading the CNS during development. However, the detailed mechanisms of differentiation and transformation of microglial cells are not fully understood. Here, we demonstrate that murine microglial cells show two morphological forms in vitro, namely, small round cells expressing CD11b, Iba1, triggering receptor expressing on myeloid cells-2 (TREM2), and weakly expressing major histocompatibility complex class II and large flat cells expressing only CD11b and Iba1. Moreover, lineage-negative bone marrow (LN) cells cultured with primary mixed glial culture cells could differentiate into only the small round microglia-like cells, despite the absence of CCR2 and Gr-1 expression. Addition of macrophage colony stimulating factor (M-CSF) to LN cell culture allowed the proliferation and expression of TREM2 in LN cells, and the addition of neutralizing anti-M-CSF antibodies suppressed the proliferation of LN cells despite the expression of TREM2. When LN cells were cultured with M-CSF, the number of small round cells in the culture was considerably low, indicating that the small round morphology of the immature cells is not maintained in the presence of only M-CSF. On the other hand, when LN cells were grown in the presence of astrocytes, the small round cells were maintained at a concentration of approximately 30% of the total population. Therefore, cell,cell contact with glial cells, especially astrocytes, may be necessary to maintain the small round shape of the immature cells expressing TREM2. [source] Changes in compaction stress distributions in roots resulting from canal preparationINTERNATIONAL ENDODONTIC JOURNAL, Issue 12 2006A. Versluis Abstract Aim, To examine if canal enlargement with instruments of controlled taper leads to more uniform stress distributions within a root, thereby reducing fracture susceptibility. Methodology, Finite element models of a mandibular incisor were constructed with round and oval canal profiles, based on measurements from extracted teeth. The shapes of rotary nickel,titanium instruments (ProTaper F1, F2, and F3 and ProFile size 30, 0.04 taper and size 30, 0.06 taper; Dentsply Maillefer) were superimposed on the canals. Equivalent stresses and circumferential stresses in the root were calculated for a compaction load. Results, The highest stresses were found at the canal wall. Round canals showed lower uniform distributions, whilst oval canals showed uneven distributions with high concentrations at the buccal and lingual canal extensions and greater stresses in the coronal and middle thirds than in the apical third. Preparation of round canals introduced only small circumferential stress increases in the apical half; preparation of oval canals produced substantial reductions where the canal was enlarged to a smooth round shape. Even where fins were not completely eliminated, the maximum stresses were still reduced by up to 15%. External distal and mesial surfaces of roots with oval canals showed moderate stress concentrations that were minimally affected by preparations, whilst stress concentrations emerged on roots with round canals when preparation sizes increased. Conclusions, The potential for reducing fracture susceptibility exists as a result of round canal profiles achieved and smooth canal taper. Even when fins were not contacted by the instrument, stresses within the root were lower and more evenly distributed than before preparation. [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] Sperm morphology in the black coral Cirrhipathes sp. (Anthozoa, Antipatharia)INVERTEBRATE BIOLOGY, Issue 3 2008Elda Gaino Abstract. Male polyps of the antipatharian Cirrhipathes sp., collected along the coral reef of Siladen Island (Sulawesi, Indonesia), were studied in order to gain an insight into the reproductive biology. Spermatocysts (maximum size 120 ,m) are located within the primary gametogenic mesenteries and are separated by mesenteric cell cytoplasmic extensions. Sperm, maturing along radial rows, have a fairly round shape and contain a series of electron-dense vesicles in the apical nuclear region. A single mitochondrion flanks the nucleus. A peculiar cup-like electron-dense body, edged with regularly spaced electron-dense granules, is interposed between the nucleus and the tail, and delimits a central region that includes two centrioles. Cross-sections of the cup-like body reveal that the distal centriole has a pericentriolar system, consisting of nine arms arranged in a radial pattern. Each arm branches into three processes that are connected to the electron-dense granules. Indirect evidence of spawning is derived from the accumulation of sperm in the gastric cavity. This process takes place through the lysis of the cells bordering the mesenteries. Intact cells of this bordering layer appear to be involved in the phagocytosis of non-expelled gametes. [source] The effects of osmotic stress on the structure and function of the cell nucleusJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2010John D. Finan Abstract Osmotic stress is a potent regulator of the normal function of cells that are exposed to osmotically active environments under physiologic or pathologic conditions. The ability of cells to alter gene expression and metabolic activity in response to changes in the osmotic environment provides an additional regulatory mechanism for a diverse array of tissues and organs in the human body. In addition to the activation of various osmotically- or volume-activated ion channels, osmotic stress may also act on the genome via a direct biophysical pathway. Changes in extracellular osmolality alter cell volume, and therefore, the concentration of intracellular macromolecules. In turn, intracellular macromolecule concentration is a key physical parameter affecting the spatial organization and pressurization of the nucleus. Hyper-osmotic stress shrinks the nucleus and causes it to assume a convoluted shape, whereas hypo-osmotic stress swells the nucleus to a size that is limited by stretch of the nuclear lamina and induces a smooth, round shape of the nucleus. These behaviors are consistent with a model of the nucleus as a charged core/shell structure pressurized by uneven partition of macromolecules between the nucleoplasm and the cytoplasm. These osmotically-induced alterations in the internal structure and arrangement of chromatin, as well as potential changes in the nuclear membrane and pores are hypothesized to influence gene transcription and/or nucleocytoplasmic transport. A further understanding of the biophysical and biochemical mechanisms involved in these processes would have important ramifications for a range of fields including differentiation, migration, mechanotransduction, DNA repair, and tumorigenesis. J. Cell. Biochem. 109: 460,467, 2010. © 2009 Wiley-Liss, Inc. [source] Value of sonography for follow-up of mediastinal lymphadenopathy in children with tuberculosisJOURNAL OF CLINICAL ULTRASOUND, Issue 3 2007Joaquim Bosch-Marcet Abstract Purpose. To assess the clinical value of sonography for the follow-up of mediastinal lymphadenopathy in children diagnosed with pulmonary tuberculosis (TB). Methods. We conducted a retrospective review of the medical records of 21 children (9 boys, 12 girls) with a mean age of 6 years (range, 7.4 months to 18 years) who had a positive intradermal tuberculin skin test. All patients underwent thorough history-taking, physical examination, frontal and lateral chest radiographs, and sonographic study of the mediastinum. The mediastinum was accessed through the suprasternal and left parasternal approaches. The presence of 1 or more masses with an ovoid or round shape and hypoechoic appearance in the anterior or middle mediastinum was recorded. A comparison was made between the results of the sonographic examination of the mediastinum before administration of anti-TB agents and after 3 months of treatment. Results. Pulmonary radiographic findings were suggestive of TB in 17 patients and were uncertain in 4 patients. Sonographic examination, however, detected mediastinal lymphadenopathy in all patients. A comparison of pretreatment mediastinal sonograms with those obtained after 3 months of anti-TB treatment showed a marked reduction of lymph node involvement in 17 patients (80.9%). In the remaining 4 patients, mediastinal lymphadenopathy was still present. Conclusion. Mediastinal sonography appears to be a valuable tool for the diagnosis of TB and in the monitoring of response to treatment in children. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007 [source] Central Pontine Signal Changes in Wilson's Disease: Distinct MRI Morphology and Sequential Changes with De-Coppering TherapyJOURNAL OF NEUROIMAGING, Issue 4 2007Sanjib Sinha DM ABSTRACT BACKGROUND AND PURPOSE Reports of central pontine myelinolysis (CPM)-like changes in Wilson's disease (WD) and its sequential changes are exceptional. The aim was to study the MRI characteristics of CPM-like changes in WD and the serial changes. METHODS Among the 121 patients of WD, twenty (M:F:9:11, age at onset: 14.2 ± 4.6 years) had features similar to CPM. All had progressive neuropsychiatric form of WD. All except five were on de-coppering treatment. None had acute deterioration or hepatic failure. Ten patients underwent repeat studies. RESULTS Twenty patients with CPM-like changes manifested with characteristic phenotype of WD. Three distinct patterns of CPM-like changes were observed: (a) characteristic round shape -7, (b) "bisected" -9, and (c) "trisected" -4. Only one had signal changes suggesting extra-pontine myelinolysis. All patients had contiguous involvement of midbrain. Serial MRI evaluation in 10 patients, at mean interval period of 17.4 ± 13.2 months, revealed complete reversal in one, partial improvement in five, and no change in three. Clinical and MRI improvement occurred pari passu, except in one. CONCLUSIONS CPM-like changes in WD are perhaps under-recognized and are distinct from the commonly known "osmotic demyelination." It is potentially reversible similar to other MRI features of WD. [source] | |||||||||||||