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961.
Sophia Pathai Stephen D. Lawn Paul G. Shiels Helen A. Weiss Colin Cook Robin Wood Clare E. Gilbert 《PloS one》2013,8(2)
Background
Cellular senescence may be a key factor in HIV-related premature biological aging. We assessed features of the corneal endothelium that are known to be associated with biological aging, and cellular senescence markers in HIV-infected adults.Methods
Case-control study of 242 HIV-infected adults and 249 matched controls. Using specular microscopy, the corneal endothelium was assessed for features of aging (low endothelial cell density [ECD], high variation in cell size, and low hexagonality index). Data were analysed by multivariable regression. CDKN2A expression (a cell senescence mediator) was measured in peripheral blood leukocytes and 8-hydroxy-2′-deoxyguanosine (8-OHDG; an oxidative DNA damage marker) levels were measured in plasma.Results
The median age of both groups was 40 years. Among HIV-infected adults, 88% were receiving antiretroviral therapy (ART); their median CD4 count was 468 cells/µL. HIV infection was associated with increased odds of variation in cell size (OR = 1.67; 95% CI: 1.00–2.78, p = 0.04). Among HIV-infected participants, low ECD was independently associated with current CD4 count <200 cells/µL (OR = 2.77; 95%CI: 1.12–6.81, p = 0.03). In participants on ART with undetectable viral load, CDKN2A expression and 8-OHDG levels were higher in those with accelerated aging, as reflected by lower ECD.Conclusions
The corneal endothelium shows features consistent with HIV-related accelerated senescence, especially among those with poor immune recovery. 相似文献962.
Water samples were collected from three sites located in the middle reach of the Njoro River, Kenya, and analysed for total phosphorus (TP), orthophosphate, ammonia‐nitrogen, and nitrate‐nitrogen to evaluate stressor sources (e.g. factories and wastewater ponds) and the general stream water quality. The stream surface water was also analysed for biochemical oxygen demand (BOD5) to provide an overview of organic matter loading. Mugo, Egerton Bridge and the canning factory sites of the Njoro River had low water quality which is likely to be due to poor farming, partially treated effluents and poor provision of sanitation facilities to the riparian communities. The concentrations of the selected nutrients did not differ significantly among the three sites, presumably due to pollution of the whole stream reach by the catchment nutrient sources. High phosphate concentrations (i.e. ~0.76 mgPO4 l?1 and ~0.87 mgTP l?1) at Canning Factory were recorded during the low flow dry season. Nitrate‐nitrogen concentrations varied significantly with water discharge which explained between 63 and 87% of the nutrient variability in the three sites. BOD5 differed significantly among the three sites, with historical effects of wastewater and factory effluent discharge being reflected in the results of Egerton Bridge and Canning Factory. The concentrations of ammonia‐nitrogen, TP and orthophosphate were higher in the wastewater than in the river water whereas nitrate‐nitrogen was lower. This study indicates that the Njoro River is stressed by nutrients from the activities within its catchment. With the increasing population, the nutrient load to the river will continue to increase and the water quality will continue to deteriorate. Reductions of nutrient loads into the river as well as provision of sanitation facilities to the riparian communities are needed to control further water degradation. 相似文献
963.
Schmidt-Wellenburg CA Engel S Visser GH 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2008,178(6):767-777
Rose Coloured Starlings (Sturnus roseus) flew repeatedly for several hours in a wind tunnel while undergoing spontaneous variation in body mass. The treatments were as follows: flying unrestrained (U), with a control harness of 1.2% of their body mass (C), or with a harness of 7.4% of their body mass, which was either applied immediately before the flight (LS) or at least 9 days in advance (LL). Energy expenditure during flight (ef in W) was measured with the Doubly Labelled Water method. Flight costs in L(S) and LL were not significantly different and therefore were pooled (L). The harness itself did not affect ef, i.e. U and C flights were not different. ef was allometrically related with body mass m (in g). The slopes were not significantly different between the treatments, but ef was increased by 5.4% in L compared to C flights (log10(ef) = 0.050 + 0.47 x log10(m) for C, and log10(ef) = 0.073 + 0.47 x log10(m) for L). The difference in ef between C, LS and LL was best explained by taking the transported mass m transp (in g) instead of m into account (log10(ef) = -0.08 + 0.54 x log10(m transp)). Flight costs increased to a lesser extent than expected from interspecific allometric comparison or aerodynamic theory, regardless of whether the increase in mass occurred naturally or artificially. We did not observe an effect of treatment on breast muscle size and wingbeat frequency. We propose that the relatively low costs at a high mass are rather a consequence of immediate adjustments in physiology and/or flight behaviour than of long-term adaptations. 相似文献
964.
David?Johannes?Wurm Lukas?Veiter Sophia?Ulonska Britta?Eggenreich Christoph?Herwig Oliver?SpadiutEmail author 《Applied microbiology and biotechnology》2016,100(20):8721-8729
Therapeutic monoclonal antibodies are mainly produced in mammalian cells to date. However, unglycosylated antibody fragments can also be produced in the bacterium Escherichia coli which brings several advantages, like growth on cheap media and high productivity. One of the most popular E. coli strains for recombinant protein production is E. coli BL21(DE3) which is usually used in combination with the pET expression system. However, it is well known that induction by isopropyl β-d-1-thiogalactopyranoside (IPTG) stresses the cells and can lead to the formation of insoluble inclusion bodies. In this study, we revisited the pET expression system for the production of a novel antibody single-chain variable fragment (scFv) with the goal of maximizing the amount of soluble product. Thus, we (1) investigated whether lactose favors the recombinant production of soluble scFv compared to IPTG, (2) investigated whether the formation of soluble product can be influenced by the specific glucose uptake rate (q s,glu) during lactose induction, and (3) determined the mechanistic correlation between the specific lactose uptake rate (q s,lac) and q s,glu. We found that lactose induction gave a much greater amount of soluble scFv compared to IPTG, even when the growth rate was increased. Furthermore, we showed that the production of soluble protein could be tuned by varying q s,glu during lactose induction. Finally, we established a simple model describing the mechanistic correlation between q s,lac and q s,glu allowing tailored feeding and prevention of sugar accumulation. We believe that this mechanistic model might serve as platform knowledge for E. coli. 相似文献
965.
The stalk, a characteristic structure of the large ribosomal subunit, is directly involved in the interaction with the soluble factors during translation. In the Mediterranean mussel Mytilus galloprovincialis, the stalk consists of one 32 kDa protein, MgP0, and two smaller, 12 kDa acidic proteins, MgP1 and MgP2, of pI 3.0 and 4.0, respectively, as revealed by analysis of purified ribosomes with electrophoresis and Western blot with a specific monoclonal antibody. Treatment of the ribosomes with alkaline phosphatase showed movement of the bands corresponding to the acidic MgP1 and MgP2 proteins to more basic pH after isoelectrofocusing, implying phosphorylation. The cDNA molecules of M. galloprovincialis ribosomal proteins MgP0, MgP1 and MgP2 and superoxide dismutase (MgSOD) were isolated from a cDNA library or constructed by RT-PCR, cloned in expression vectors and expressed in Escherichia coli. The recombinant proteins were purified with immobilized metal ion affinity chromatography (IMAC) and identified with immunoblotting. Exposure of mussels at cadmium and sorbitol and analysis of gill tissue extracts showed over expression of MgP0 protein. 相似文献
966.
Dimas K Hatziantoniou S Tseleni S Khan H Georgopoulos A Alevizopoulos K Wyche JH Pantazis P Demetzos C 《Apoptosis : an international journal on programmed cell death》2007,12(4):685-694
Labd-14-ene-8, 13-diol (sclareol) is a labdane-type diterpene, which has demonstrated significant cytotoxic activity against
human leukemic cell lines, but its effect on solid tumor-derived cells is uknown. Here, we demonstrate that addition of sclareol
to cultures of human colon cancer HCT116 cells results in inhibition of DNA synthesis, arrest of cells at the G1 phase of the cell cycle, activation of caspases-8, -9, PARP degradation, and DNA fragmentation, events characteristic of
induction of apoptosis. Intraperitoneal (ip) administration of sclareol alone, at the maximum tolerated dose, was unable to
induce suppression of growth of HCT116 tumors established as xenografts in immunodeficient SCID mice. In contrast, ip administration
of liposome-encapsulated sclareol, following a specific schedule, induced suppression of tumor growth by arresting tumor cell
proliferation as assessed by detecting the presence of the cell proliferation-associated nuclear protein, Ki67, in thin tumor
sections. These findings suggest that sclareol incorporated into liposomes may possess chemotherapeutic potential for the
treatment of colorectal and other types of human cancer. 相似文献
967.
Bharat Rekhi Sophia George Bhulaxmi Madur RF Chinoy Rajesh Dikshit Amita Maheshwari 《Diagnostic pathology》2008,3(1):1-7
Introduction
Intravascular lesions of the hand comprise reactive and neoplastic entities. The clinical diagnosis of such lesions is often difficult, and usually requires pathologic examination. We present the largest series to date of intravascular lesions affecting the hand.Methods
A retrospective review of intravascular (arterial and venous) lesions involving the hand was conducted. Data regarding clinicopathologic findings were analyzed.Results
We identified 10 patients with intravascular lesions of their hands including thromboemboli (n = 3), reactive intravascular conditions such as papillary endothelial hyperplasia or Masson's tumor (n = 2) and fasciitis (n = 1), as well as vascular neoplasms including pyogenic granuloma (n = 2) and angioleiomyoma (n = 2).Conclusion
Blood vessel injury and/or venous thrombosis may predispose to several intravascular lesions of the hand. Recognition of reactive entities from neoplastic conditions is important. 相似文献968.
Tambor JH Ren H Ushinsky S Zheng Y Riemens A St-Francois C Tsang A Powlowski J Storms R 《Applied microbiology and biotechnology》2012,93(1):203-214
The hydrolysis of cellulose into fermentable sugars is a costly and rate-limiting step in the production of biofuels from
renewable feedstocks. Developing new cellulase systems capable of increased cellulose hydrolysis rates would reduce biofuel
production costs. With this in mind, we screened 55 fungal endoglucanases for their abilities to be expressed at high levels
by Aspergillus niger and to hydrolyze amorphous cellulose at rates significantly greater than that obtained with TrCel5A, one of the major endoglucanases
in the Trichoderma reesei cellulase system. This screen identified three endoglucanases, Aureobasidium pullulans ApCel5A, Gloeophyllum trabeum GtCel12A and Sporotrichum thermophile StCel5A. We determined that A. niger expressed the three endoglucanases at relatively high levels (≥0.3 g/l) and that the hydrolysis rate of ApCel5A and StCel5A
with carboxymethylcellulose 4M as substrate was five and two times greater than the T. reesei Cel5A. The ApCel5A, GtCel12A and StCel5A enzymes also demonstrated significant synergy with Cel7A/CbhI, the major exoglucanase
in the T. reesei cellulase system. The three endoglucanases characterized in this study are, therefore, promising candidate endoglucanases
for developing new cellulase systems with increased rates of cellulose saccharification. 相似文献
969.
Paul Thompson Riza Theresa Batista-Navarro Georgios Kontonatsios Jacob Carter Elizabeth Toon John McNaught Carsten Timmermann Michael Worboys Sophia Ananiadou 《PloS one》2016,11(1)
Historical text archives constitute a rich and diverse source of information, which is becoming increasingly readily accessible, due to large-scale digitisation efforts. However, it can be difficult for researchers to explore and search such large volumes of data in an efficient manner. Text mining (TM) methods can help, through their ability to recognise various types of semantic information automatically, e.g., instances of concepts (places, medical conditions, drugs, etc.), synonyms/variant forms of concepts, and relationships holding between concepts (which drugs are used to treat which medical conditions, etc.). TM analysis allows search systems to incorporate functionality such as automatic suggestions of synonyms of user-entered query terms, exploration of different concepts mentioned within search results or isolation of documents in which concepts are related in specific ways. However, applying TM methods to historical text can be challenging, according to differences and evolutions in vocabulary, terminology, language structure and style, compared to more modern text. In this article, we present our efforts to overcome the various challenges faced in the semantic analysis of published historical medical text dating back to the mid 19th century. Firstly, we used evidence from diverse historical medical documents from different periods to develop new resources that provide accounts of the multiple, evolving ways in which concepts, their variants and relationships amongst them may be expressed. These resources were employed to support the development of a modular processing pipeline of TM tools for the robust detection of semantic information in historical medical documents with varying characteristics. We applied the pipeline to two large-scale medical document archives covering wide temporal ranges as the basis for the development of a publicly accessible semantically-oriented search system. The novel resources are available for research purposes, while the processing pipeline and its modules may be used and configured within the Argo TM platform. 相似文献
970.