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排序方式: 共有1021条查询结果,搜索用时 15 毫秒
971.
Hannah E. Steinberg Natalie M. Bowman Andrea Diestra Cusi Ferradas Paul Russo Daniel E. Clark Deanna Zhu Ruben Magni Edith Malaga Monica Diaz Viviana Pinedo-Cancino Cesar Ramal Asayag Maritza Caldern Vern B. Carruthers Lance A. Liotta Robert H. Gilman Alessandra Luchini the Toxoplasmosis working group in Peru Bolivia 《PLoS neglected tropical diseases》2021,15(3)
BackgroundDiagnosis of toxoplasmic encephalitis (TE) is challenging under the best clinical circumstances. The poor clinical sensitivity of quantitative polymerase chain reaction (qPCR) for Toxoplasma in blood and CSF and the limited availability of molecular diagnostics and imaging technology leaves clinicians in resource-limited settings with few options other than empiric treatment.Methology/principle findingsHere we describe proof of concept for a novel urine diagnostics for TE using Poly-N-Isopropylacrylamide nanoparticles dyed with Reactive Blue-221 to concentrate antigens, substantially increasing the limit of detection. After nanoparticle-concentration, a standard western blotting technique with a monoclonal antibody was used for antigen detection. Limit of detection was 7.8pg/ml and 31.3pg/ml of T. gondii antigens GRA1 and SAG1, respectively. To characterize this diagnostic approach, 164 hospitalized HIV-infected patients with neurological symptoms compatible with TE were tested for 1) T. gondii serology (121/147, positive samples/total samples tested), 2) qPCR in cerebrospinal fluid (11/41), 3) qPCR in blood (10/112), and 4) urinary GRA1 (30/164) and SAG1 (12/164). GRA1 appears to be superior to SAG1 for detection of TE antigens in urine. Fifty-one HIV-infected, T. gondii seropositive but asymptomatic persons all tested negative by nanoparticle western blot and blood qPCR, suggesting the test has good specificity for TE for both GRA1 and SAG1. In a subgroup of 44 patients, urine samples were assayed with mass spectrometry parallel-reaction-monitoring (PRM) for the presence of T. gondii antigens. PRM identified antigens in 8 samples, 6 of which were concordant with the urine diagnostic.Conclusion/significancesOur results demonstrate nanoparticle technology’s potential for a noninvasive diagnostic test for TE. Moving forward, GRA1 is a promising target for antigen based diagnostics for TE. 相似文献
972.
Manuela Morleo Simona Brillante Umberto Formisano Luigi Ferrante Fabrizia Carbone Daniela Iaconis Alessandro Palma Viviana Buonomo Angela Serena Maione Paolo Grumati Carmine Settembre Brunella Franco 《The EMBO journal》2021,40(4)
Autophagy is a lysosome‐dependent degradation pathway essential to maintain cellular homeostasis. Therefore, either defective or excessive autophagy may be detrimental for cells and tissues. The past decade was characterized by significant advances in molecular dissection of stimulatory autophagy inputs; however, our understanding of the mechanisms that restrain autophagy is far from complete. Here, we describe a negative feedback mechanism that limits autophagosome biogenesis based on the selective autophagy‐mediated degradation of ATG13, a component of the ULK1 autophagy initiation complex. We demonstrate that the centrosomal protein OFD1 acts as bona fide autophagy receptor for ATG13 via direct interaction with the Atg8/LC3/GABARAP family of proteins. We also show that patients with Oral‐Facial‐Digital type I syndrome, caused by mutations in the OFD1 gene, display excessive autophagy and that genetic inhibition of autophagy in a mouse model of the disease, significantly ameliorates polycystic kidney, a clinical manifestation of the disorder. Collectively, our data report the discovery of an autophagy self‐regulated mechanism and implicate dysregulated autophagy in the pathogenesis of renal cystic disease in mammals. 相似文献
973.
974.
975.
Myriam Carolina Peichoto Silvia Matilde Mazza Viviana Griselda Solís Neffa 《Plant Systematics and Evolution》2008,276(3-4):177-189
Our aim was to assess the degree of morphological differentiation of a group of taxa of Schizachyrium Nees, which presents similar inflorescences and shares habitat and geographic areas: Schizachyrium bimucronatum, S. condensatum, S. lactiflorum, S. microstachyum subsp. microstachyum, S. microstachyum subsp. elongatum, and S. plumigerum. To accomplish this purpose, 22 exomorphological traits were analyzed using multivariate methods. The results obtained support the identity of Schizachyrium condensatum and related species as independent taxa. In addition, the analysis evidences the reliability of several inflorescence characters, which had not been previously considered in the identification of the different taxa. Based upon the information obtained, a new identification key for these taxa was constructed. 相似文献
976.
Jun Nagai Arash Bellafard Zhe Qu Xinzhu Yu Matthias Ollivier Mohitkumar R. Gangwani Blanca Diaz-Castro Giovanni Coppola Sarah M. Schumacher Peyman Golshani Viviana Gradinaru Baljit S. Khakh 《Neuron》2021,109(14):2256-2274.e9
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977.
A simulation model is used to examine the errors in estimating parasitized and nonparasitized host densities independently
with Southwood's graphical technique. This technique is accurate when parasitoid attack occurs prior to the sampling period
(e.g. the previous life stage of the host). When this is not the case, the parasitized host density is estimated accurately,
but the unparasitized host density is over estimated by those individuals that are sampled as healthy prior to attack. This
error is neglible at low levels of parasitism (<20% parasitized), but increases with increasing parasitism. Of the biological
parameters tested, only the parasitoid attack pattern (shape of the parasitoid attack curve) has a significant influence on
the magnitude of this error. A generalized simulation model is presented for evaluating errors in estimates of seasonal parasitism
for specific host-parasitoid interactions.
University of Rhode Island, Agricultural Experiment Station Journal, Article Number 2479. 相似文献
978.
Aleksandr Gavrin Patrick C Loughlin Ella Brear Oliver W Griffith Frank Bedon Marianne Suter Grotemeyer Viviana Escudero Maria Reguera Yihan Qu Siti N Mohd-Noor Chi Chen Marina Borges Osorio Doris Rentsch Manuel Gonzlez-Guerrero David A Day Penelope Mary Collina Smith 《Plant physiology》2021,186(1):581
979.
Josefina María Villegas Clarisa María Torres-Bugeau Rosana Chehín Martha Inés Burgos Gerardo Daniel Fidelio María Regina Rintoul Viviana Andrea Rapisarda 《Biochimie》2013
Development of an artificial enzyme with activity and structure comparable to that of natural enzymes is an important goal in biological chemistry. Respiratory NADH dehydrogenase-2 (NDH-2) of Escherichia coli is a peripheral membrane-bound flavoprotein, belonging to a group of enzymes with scarce structural information. By eliminating the C-terminal region of NDH-2, a water soluble version with significant enzymatic activity was previously obtained. Here, NDH-2 structural features were established, in comparison to those of the truncated version. Far-UV circular dichroism, Fourier transform infrared spectroscopy and limited proteolysis analysis showed that the overall structure of both proteins was similar at 30 °C. Experimental data agree with the predicted NDH-2 structure (PDB: 1OZK). The absence of C-terminal region stabilized in ∼5–10 °C the truncated protein conformation. However, truncation impaired enzymatic activity at low temperatures, probably due to the weak interaction of the mutant protein with FAD cofactor. 相似文献
980.