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61.
Shim J Perdigou C Chen ER Bertoldi K Reis PM 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(16):5978-5983
We introduce a class of continuum shell structures, the Buckliball, which undergoes a structural transformation induced by buckling under pressure loading. The geometry of the Buckliball comprises a spherical shell patterned with a regular array of circular voids. In order for the pattern transformation to be induced by buckling, the possible number and arrangement of these voids are found to be restricted to five specific configurations. Below a critical internal pressure, the narrow ligaments between the voids buckle, leading to a cooperative buckling cascade of the skeleton of the ball. This ligament buckling leads to closure of the voids and a reduction of the total volume of the shell by up to 54%, while remaining spherical, thereby opening the possibility of encapsulation. We use a combination of precision desktop-scale experiments, finite element simulations, and scaling analyses to explore the underlying mechanics of these foldable structures, finding excellent qualitative and quantitative agreement. Given that this folding mechanism is induced by a mechanical instability, our Buckliball opens the possibility for reversible encapsulation, over a wide range of length scales. 相似文献
62.
Benedikt Bosbach Shayu Deshpande Ferdinand Rossi Jae-Hung Shieh Gunhild Sommer Elisa de Stanchina Darren R. Veach Joseph M. Scandura Katia Manova-Todorova Malcolm A. S. Moore Cristina R. Antonescu Peter Besmer 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(34):E2276
63.
Meirelles K Benedict LA Dombkowski D Pepin D Preffer FI Teixeira J Tanwar PS Young RH MacLaughlin DT Donahoe PK Wei X 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(7):2358-2363
Women with late-stage ovarian cancer usually develop chemotherapeutic-resistant recurrence. It has been theorized that a rare cancer stem cell, which is responsible for the growth and maintenance of the tumor, is also resistant to conventional chemotherapeutics. We have isolated from multiple ovarian cancer cell lines an ovarian cancer stem cell-enriched population marked by CD44, CD24, and Epcam (3+) and by negative selection for Ecadherin (Ecad-) that comprises less than 1% of cancer cells and has increased colony formation and shorter tumor-free intervals in vivo after limiting dilution. Surprisingly, these cells are not only resistant to chemotherapeutics such as doxorubicin, but also are stimulated by it, as evidenced by the significantly increased number of colonies in treated 3+Ecad- cells. Similarly, proliferation of the 3+Ecad- cells in monolayer increased with treatment, by either doxorubicin or cisplatin, compared with the unseparated or cancer stem cell-depleted 3-Ecad+ cells. However, these cells are sensitive to Mullerian inhibiting substance (MIS), which decreased colony formation. MIS inhibits ovarian cancer cells by inducing G1 arrest of the 3+Ecad- subpopulation through the induction of cyclin-dependent kinase inhibitors. 3+Ecad- cells selectively expressed LIN28, which colocalized by immunofluorescence with the 3+ cancer stem cell markers in the human ovarian carcinoma cell line, OVCAR-5, and is also highly expressed in transgenic murine models of ovarian cancer and in other human ovarian cancer cell lines. These results suggest that chemotherapeutics may be stimulative to cancer stem cells and that selective inhibition of these cells by treating with MIS or targeting LIN28 should be considered in the development of therapeutics. 相似文献
64.
Arinaminpathy N Ratmann O Koelle K Epstein SL Price GE Viboud C Miller MA Grenfell BT 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(8):3173-3177
Large-scale immunization has profoundly impacted control of many infectious diseases such as measles and smallpox because of the ability of vaccination campaigns to maintain long-term herd immunity and, hence, indirect protection of the unvaccinated. In the case of human influenza, such potential benefits of mass vaccination have so far proved elusive. The central difficulty is a considerable viral capacity for immune escape; new pandemic variants, as well as viral escape mutants in seasonal influenza, compromise the buildup of herd immunity from natural infection or deployment of current vaccines. Consequently, most current influenza vaccination programs focus mainly on protection of specific risk groups, rather than mass prophylactic protection. Here, we use epidemiological models to show that emerging vaccine technologies, aimed at broad-spectrum protection, could qualitatively alter this picture. We demonstrate that sustained immunization with such vaccines could--through potentially lowering transmission rates and improving herd immunity--significantly moderate both influenza pandemic and seasonal epidemics. More subtly, phylodynamic models indicate that widespread cross-protective immunization could slow the antigenic evolution of seasonal influenza; these effects have profound implications for a transition to mass vaccination strategies against human influenza, and for the management of antigenically variable viruses in general. 相似文献
65.
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67.
Carneiro Borba C de Lourdes Chauffaille M Saeed Sanabani S Saeed Sanabnai S Folloni Fernandes J Aiko Kumeda C Rodrigues Pereira Velloso ED Jarandilha dos Santos K Puato Vieira Pupim M Hamerschlak N Odone Filho V Bendit I 《Acta haematologica》2012,127(3):165-169
This paper chronicles a 2-year-old girl who presented with acute leukemia/lymphoma syndrome of the T cell immunophenotype. At this time, the cytogenetic analysis of her bone marrow cells showed a reciprocal translocation between the short arm of chromosome 12 and the long arm of chromosome 13, t(12;13)(p13;q14). The immunophenotyping of bone marrow blast cells by flow cytometry revealed a population of cells positive for CD56, CD117, CD45, partial CD33, partial HLA-DR, CD13, CD7, CD2 and CD5. Therefore, a diagnosis of acute leukemia with a mixed T cell/myeloid phenotype was made. The patient had a poor response to classic T cell acute lymphocytic leukemia/lymphoma therapy; thus, her treatment was changed to a myeloid leukemia protocol, which produced a good response. She underwent a successful cord blood transplantation from an unrelated HLA partially matched donor. The coexistence of these two phenotypes prompts questions about the existence of clonal instability, which might influence the choice of therapy. The rarity of the t(12;13)(p13;q14) and the coexistence of T cell/myeloid markers suggest a nonrandom association. To the best of our knowledge, this is the first reported case in which a cell clone bearing a t(12;13)(p13;q14) translocation in a mixed T cell/myeloid lesion was detected. 相似文献
68.
69.
Lionnet F Hammoudi N Stojanovic KS Avellino V Grateau G Girot R Haymann JP 《Haematologica》2012,97(8):1136-1141
Background
Hemoglobin sickle cell disease is one of the most frequent hemoglobinopathies. Surprisingly, few studies have been dedicated to this disease, currently considered to be a mild variant of homozygous sickle cell disease. The aim of this study was to update our knowledge about hemoglobin sickle cell disease.Design and Methods
The study involved a single center series of 179 patients. Clinical and biological data were collected with special attention to the assessment of pulmonary arterial hypertension and nephropathy.Results
Hemoglobin sickle cell diagnosis was delayed and performed in adulthood in 29% of cases. Prevalence of hospitalized painful vasoocclusive crisis, acute chest syndrome and priapism was 36%, 20% and 20%, respectively. The most common chronic organ complications were retinopathy and sensorineural otological disorders in 70% and 29% of cases. Indeed, prevalence of complications reported in homozygous sickle cell disease, such as nephropathy, suspicion of pulmonary hypertension, strokes and leg ulcers was rather low (13%, 4% and 1%, respectively). Phlebotomy performed in 36% of this population (baseline hemoglobin 11.5 g/dL) prevented recurrence of acute events in 71% of cases.Conclusions
Our data suggest that hemoglobin sickle cell disease should not be considered as a mild form of sickle cell anemia but as a separate disease with a special emphasis on viscosity-associated otological and ophthalmological disorders, and with a low prevalence of vasculopathy (strokes, pulmonary hypertension, ulcers and nephropathy). Phlebotomy was useful in reducing acute events and a wider use of this procedure should be further investigated. 相似文献70.
Side of onset does not influence cognition in newly diagnosed untreated Parkinson's disease patients
Roberto Erro Gabriella Santangelo Marina Picillo Carmine Vitale Marianna Amboni Katia Longo Flavio Giordano Marcello Moccia Paolo Barone Maria Teresa Pellecchia 《Parkinsonism & related disorders》2013,19(2):256-259
BackgroundA relation between the side of motor onset and cognitive impairment in early PD has been reported, suggesting that the asymmetric degeneration affecting subcortical regions may play a pivotal role in lateralized cognitive function. However, evidences are controversial and all previous studies were performed on treated patients, though it is known that dopaminergic therapy can affect cognition in PD.MethodsSixty-nine early untreated PD patients underwent an extensive neuropsychological battery exploring memory, visuospatial and attention/executive functions. Patients were divided with respect of the side of onset (right vs. left) and further grouped according to motor phenotype (tremor vs. rigidity-bradykinesia). Multivariate analysis of variance has been carried out to compare clinical and neuropsychological data between subgroups.ResultsThere were no differences in any neuropsychological task between right-sided and left-sided onset subgroups, irrespective of tremor dominant or rigid-bradykinetic phenotype. Age at onset was significantly higher in patients with any cognitive impairment as compared with patients without (66.7 ± 3.2 vs. 56.3 ± 6.8 years, p = 0.001).ConclusionSide of motor onset is not a major determinant for developing lateralized cognitive deficits in newly diagnosed untreated PD patients. 相似文献