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1.
Christopher I. Jarvis Amy Gimma Flavio Finger Tim P. Morris Jennifer A. Thompson Olivier le Polain de Waroux W. John Edmunds Sebastian Funk Thibaut Jombart 《PLoS computational biology》2022,18(5)
The fraction of cases reported, known as ‘reporting’, is a key performance indicator in an outbreak response, and an essential factor to consider when modelling epidemics and assessing their impact on populations. Unfortunately, its estimation is inherently difficult, as it relates to the part of an epidemic which is, by definition, not observed. We introduce a simple statistical method for estimating reporting, initially developed for the response to Ebola in Eastern Democratic Republic of the Congo (DRC), 2018–2020. This approach uses transmission chain data typically gathered through case investigation and contact tracing, and uses the proportion of investigated cases with a known, reported infector as a proxy for reporting. Using simulated epidemics, we study how this method performs for different outbreak sizes and reporting levels. Results suggest that our method has low bias, reasonable precision, and despite sub-optimal coverage, usually provides estimates within close range (5–10%) of the true value. Being fast and simple, this method could be useful for estimating reporting in real-time in settings where person-to-person transmission is the main driver of the epidemic, and where case investigation is routinely performed as part of surveillance and contact tracing activities. 相似文献
2.
Matteo Monieri Paolo Rainone Angelina Sacchi Alessandro Gori Anna Maria Gasparri Angela Coliva Antonio Citro Benedetta Ferrara Martina Policardi Silvia Valtorta Arianna Pocaterra Massimo Alfano Dean Sheppard Lorenzo Piemonti Rosa Maria Moresco Angelo Corti Flavio Curnis 《International journal of biological sciences》2023,19(1):156
Rationale: The αvβ6- and αvβ8-integrins, two cell-adhesion receptors upregulated in many tumors and involved in the activation of the latency associated peptide (LAP)/TGFβ complex, represent potential targets for tumor imaging and therapy. We investigated the tumor-homing properties of a chromogranin A-derived peptide containing an RGDL motif followed by a chemically stapled alpha-helix (called “5a”), which selectively recognizes the LAP/TGFβ complex-binding site of αvβ6 and αvβ8.Methods: Peptide 5a was labeled with IRDye 800CW (a near-infrared fluorescent dye) or with 18F-NOTA (a label for positron emission tomography (PET)); the integrin-binding properties of free peptide and conjugates were then investigated using purified αvβ6/αvβ8 integrins and various αvβ6/αvβ8 single - or double-positive cancer cells; tumor-homing, biodistribution and imaging properties of the conjugates were investigated in subcutaneous and orthotopic αvβ6-positive carcinomas of the pancreas, and in mice bearing subcutaneous αvβ8-positive prostate tumors.Results: In vitro studies showed that 5a can bind both integrins with high affinity and inhibits cell-mediated TGFβ activation. The 5a-IRDye and 5a-NOTA conjugates could bind purified αvβ6/αvβ8 integrins with no loss of affinity compared to free peptide, and selectively recognized various αvβ6/αvβ8 single- or double-positive cancer cells, including cells from pancreatic carcinoma, melanoma, oral mucosa, bladder and prostate cancer. In vivo static and dynamic optical near-infrared and PET/CT imaging and biodistribution studies, performed in mice with subcutaneous and orthotopic αvβ6-positive carcinomas of the pancreas, showed high target-specific uptake of fluorescence- and radio-labeled peptide by tumors and low non-specific uptake in other organs and tissues, except for excretory organs. Significant target-specific uptake of fluorescence-labeled peptide was also observed in mice bearing αvβ8-positive prostate tumors.Conclusions: The results indicate that 5a can home to αvβ6- and/or αvβ8-positive tumors, suggesting that this peptide can be exploited as a ligand for delivering imaging or anticancer agents to αvβ6/αvβ8 single- or double-positive tumors, or as a tumor-homing inhibitor of these TGFβ activators. 相似文献
3.
UTRdb and UTRsite: specialized databases of sequences and functional elements of 5′ and 3′ untranslated regions of eukaryotic mRNAs. Update 2002 下载免费PDF全文
4.
Besides the excavation of underground nest chambers, Atta vollenweideri grass-cutting ants build ventilation turrets on the topmost openings of their huge nests. Turret construction was studied in a laboratory colony, addressing the question whether turrets are simply heaps of disposed soil, or result from the import and a particular spatial arrangement of materials. The colony was daily offered different building materials, i.e., clay, coarse and fine sands, which workers collected and deposited around a nest opening to construct a turret. After 10 days, the spatial arrangement of the different building materials, offered either simultaneously or consecutively in independent experiments, was characterized via thin sections and micromorphological analysis of the turret’s walls. Workers did not select particular materials to be imported for turret building, but were selective in their spatial distribution and assembly into the turret structure. Particular types of microstructures were observed depending on the available materials, such as simple piles of sands, porous fabrics only composed of clay pellets, or fabrics with clay and sands combined. Turrets were very dynamic structures: while most imported materials were initially piled up at the shortest distance from the source, a marked subsequent material redistribution occurred as the turret grew, resulting in a new, mixed structure. Material re-assembly was particular evident when clay and sands were offered consecutively: a remarkable tendency to construct microstructures combining both materials was observed, i.e., clays were mobilized and included in sandy walls, and sands were intercalated in much compact clay walls. Irrespective of the materials used, walls showed a marked regular porosity in the range 50–60%, with the exception of secondary galleries that occasionally permeated the turret structure, which evinced lower porosity and therefore a more compact microstructure. Ants appeared to respond to local variations in the structural stability of the construction, since clay coatings smoothed and reinforced the surface of unstable sandy gallery walls. The observed building responses appear to be aimed at the maintenance of a porous yet mechanically-stable structure. The attained turret porosity may represent a compromise between high structural stability and low construction costs because of savings in material import. 相似文献
5.
Rat liver casein kinase TS (Ck-TS) having quarternary structure α2β2, autophosphorylates at its 25 kDa, β-subunits, incorporating up to 1.2 mol P/mol enzyme. According to their effects on the autophosphorylation pattern the effectors of Ck-TS activity can be grouped into 3 classes: (i) inhibitors, like heparin, which also prevent the autophosphorylation of the β-subunit; (ii) stimulators possessing several amino groups (like spermine) which increase the autophosphorylation at the β-subunit; (iii) stimulators possessing several guanido groups, like protamines and related peptides, which prevent the phosphorylation of the β-subunit, while promoting the autophosphorylation of the 38 kDa α-subunit. In the presence of such polyarginyl effectors the 130 kDa Ck-TS is converted into forms with higher sedimentation coefficient. 相似文献
6.
McCullough MJ Jorge JJ Lejbkowicz F Lefler E Nassar F Clemons KV Stevens DA 《Mycopathologia》2004,158(1):39-41
Candida albicans and C. dubliniensis genotype differences among Israeli ethnic groups were assessed. Isolates from Jews (51), Arabs (35) and Druze (25) were genotyped. The distributions among ethnic groups were not different, however they differed (p = 0.002) from global populations. Therefore, C. albicans and C. dubliniensis genotype distribution differences in Israel are related to changes in all ethnic groups. 相似文献
7.
Hypnea musciformis is the only species so far exploited in Brazil as raw material for the production of k-carrageenan. Due to the erratic production in space and time, increasing harvest and transportation costs, experiments have been performed in order to assess the viability of H. musciformis mariculture.In nature the species occurs as an epiphyte, and so mariculture using artificial substrates that simulated the natural host of the species was tried. These substrates were attached, at regular intervals, to linear ropes. In the sea, these ropes were stretched between cement blocks.Seeding occurs naturally, by means of spores, or detached pieces of H. musciformis scattered in the water column that get entangled on the ropes. The best yields (0.54 wet kg m–1 month–1) were obtained with unthreaded rope substrates maintained in a vertical position by small rafts. Production is highest in the first 18 m off the rocky shore (0–2.1 m deep), at the highest substrate density utilized (10 m–1), 2–3 months after installing the ropes in seawater. The main factor controlling seasonal production is water movement. 相似文献
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10.
María C. Castro Flavio Francini Juan J. Gagliardino María L. Massa 《Biochimica et Biophysica Acta (BBA)/General Subjects》2014