84 research outputs found
Kidney Injuries in Sickle Cell Disease
Sickle cell disease (SCD), characterized by the presence of unstable sickle hemoglobin in the homozygous state (HbSS), results in progressive organ damage and early mortality with the median age of death in the 40s. The kidney is one of the most severely affected organs in SCD. Kidney diseases gradually develop in individuals with SCD. Microalbuminuria is evident in childhood, progressing to apparent proteinuria, deteriorating glomerular filtration rate (GFR) in early adulthood. While CKD becomes prevalent in adults. Moreover, among SCD patients, exacerbation of anemia is an independent risk factor for acute kidney injury (AKI) which is a predisposing factor for CKD and End Stage Renal Diseases (ESRD), altogether contributing to 16–18% mortality among this patients’ population. The pathogenesis of renal diseases in SCD is not completely understood. While epidemiological studies have shown a strong association between rate of hemolysis, severity of anemia and CKD, intrinsic inflammatory, oxidative and hypercoagulative stress that contribute to the characteristic endothelial dysfunction also promotes development of renal diseases in SCD. This chapter will elaborately discuss current research on the pathogenesis of AKI, AKI-to-CKD transition and future research perspectives for development of novel therapeutic strategies
Optimizing Supply Decisions in a B2B Exchange Environment
The advent of the Internet is reshaping the landscape of B2B commerce in a significant manner. Emerging e-marketplaces are offering firms an opportunity to optimize their supply chain decisions across a variety of sourcing scenarios. In this paper, we have specifically focused on decision-making for systematic sourcing of make-to-order (MTO) items. We minimize sourcing and purchasing costs in the presence of fixed costs, shared capacity constraints, and volume-based discounts for bundles of items. We consider a private-exchange that facilitates collaborative sourcing and enables a buyer firm to aggregate demand across different units to gain savings from volume-based discounts on individual items or groups of items, avoiding the duplication of tooling investments, and reducing setup costs. Due to the computational complexity of this problem, we develop a heuristic procedure based on Lagrangian relaxation technique to solve the problem. The computational results show that the procedure is effective under a variety of scenarios
Identification of new genes in human chromosome 3 contig 7 by graphical representation technique
The rapidly growing library of genomic length sequences and the working draft of the human genome sequence imply a concomitant need to determine new methods to analyse the sequences for rapid identification of new genes and their functions. We have developed a graphical technique for quick determination of probable coding regions in DNA sequences. In this article we apply this technique to the new sequence data from human chromosome 3 contig 7 to test the efficacy of the proposed system in a live case, and also compare with results from other genomic sequences. We report here a sampling of sequence segments that pass theoretical tests of likelihood of being genes and list several that have close homology with sequences from the expressed sequence tag (EST) databases. We also comment on the possible use of the graphical representation technique in the shotgun method of gene sequencing
Essential role for ALCAM gene silencing in megakaryocytic differentiation of K562 cells
<p>Abstract</p> <p>Background</p> <p>Activated leukocyte cell adhesion molecule (ALCAM/CD166) is expressed by hematopoietic stem cells. However, its role in hematopoietic differentiation has not previously been defined.</p> <p>Results</p> <p>In this study, we show that ALCAM expression is silenced in erythromegakaryocytic progenitor cell lines. In agreement with this finding, the ALCAM promoter is occupied by GATA-1 <it>in vivo</it>, and a cognate motif at -850 inhibited promoter activity in K562 and MEG-01 cells. Gain-of-function studies showed that ALCAM clusters K562 cells in a process that requires PKC. Induction of megakaryocytic differentiation in K562 clones expressing ALCAM activated PKC-δ and triggered apoptosis.</p> <p>Conclusions</p> <p>There is a lineage-specific silencing of ALCAM in bi-potential erythromegakaryocytic progenitor cell lines. Marked apoptosis of ALCAM-expressing K562 clones treated with PMA suggests that aberrant ALCAM expression in erythromegakaryocytic progenitors may contribute to megakaryocytopenia.</p
Optimal Voting Rule and Minimization of Total Error Rate in Cooperative Spectrum Sensing for Cognitive Radio Networks, Journal of Telecommunications and Information Technology, 2021, nr 1
In cognitive radio technology, spectrum sensing is essential for detecting spectrum holes which may be allotted to secondary users. In this paper, an optimal voting rule is used for cooperative spectrum sensing while minimizing the total error rate (TER). The proposed spectrum sensing method is more energy-efficient and may be implemented in practice. It is relied upon in an improved energy detector whose utilization depends on the presence or absence of the primary user. Expressions for false alarm and missed detection probabilities are derived in the paper as well. Overall performance is analyzed both for AWGN and Rayleigh fading channels, in the presence of additive white Gaussian noise (AWGN). The optimum voting rule is applied to the cooperative spectrum sensing process in order to identify the optimum number of sensing nodes and the detection threshold. Finally, an energy-efficient spectrum sensing algorithm is proposed, requiring a lower number of cognitive users for a given error bound
Efficacy of nano-hydroxyapatite prepared by an aqueous solution combustion technique in healing bone defects of goat
The present study was undertaken to evaluate porous hydroxyapatite (HAp), the powder of which was prepared by a novel aqueous solution combustion technique, as a bone substitute in healing bone defects in vivo, as assessed by radiologic and histopathologic methods, oxytetracycline labeling, and angiogenic features in Bengal goat. Bone defects were created in the diaphysis of the radius and either not filled (group I) or filled with a HAp strut (group II). The radiologic study in group II showed the presence of unabsorbed implants which acted as a scaffold for new bone growth across the defect, and the quality of healing of the bone defect was almost indistinguishable from the control group, in which the defect was more or less similar, although the newly formed bony tissue was more organized when HAp was used. Histologic methods showed complete normal ossification with development of Haversian canals and well-defined osteoblasts at the periphery in group II, whereas the control group had moderate fibro-collagenization and an adequate amount of marrow material, fat cells, and blood vessels. An oxytetracycline labeling study showed moderate activity of new bone formation with crossing-over of new bone trabeculae along with the presence of resorption cavities in group II, whereas in the control group, the process of new bone formation was active from both ends and the defect site appeared as a homogenous non-fluoroscent area. Angiograms of the animals in the control group showed uniform angiogenesis in the defect site with establishment of trans-transplant angiogenesis, whereas in group II there was complete trans-transplant shunting of blood vessel communication. Porous HAp ceramic prepared by an aqueous combustion technique promoted bone formation over the defect, confirming their biologic osteoconductive property
Raman spectroscopy in head and neck cancer
In recent years there has been much interest in the use of optical diagnostics in cancer detection. Early diagnosis of cancer affords early intervention and greatest chance of cure. Raman spectroscopy is based on the interaction of photons with the target material producing a highly detailed biochemical 'fingerprint' of the sample. It can be appreciated that such a sensitive biochemical detection system could confer diagnostic benefit in a clinical setting. Raman has been used successfully in key health areas such as cardiovascular diseases, and dental care but there is a paucity of literature on Raman spectroscopy in Head and Neck cancer. Following the introduction of health care targets for cancer, and with an ever-aging population the need for rapid cancer detection has never been greater. Raman spectroscopy could confer great patient benefit with early, rapid and accurate diagnosis. This technique is almost labour free without the need for sample preparation. It could reduce the need for whole pathological specimen examination, in theatre it could help to determine margin status, and finally peripheral blood diagnosis may be an achievable target
Acute otitis externa: Consensus definition, diagnostic criteria and core outcome set development.
OBJECTIVE: Evidence for the management of acute otitis externa (AOE) is limited, with unclear diagnostic criteria and variably reported outcome measures that may not reflect key stakeholder priorities. We aimed to develop 1) a definition, 2) diagnostic criteria and 3) a core outcome set (COS) for AOE. STUDY DESIGN: COS development according to Core Outcome Measures in Effectiveness Trials (COMET) methodology and parallel consensus selection of diagnostic criteria/definition. SETTING: Stakeholders from the United Kingdom. SUBJECTS AND METHODS: Comprehensive literature review identified candidate items for the COS, definition and diagnostic criteria. Nine individuals with past AOE generated further patient-centred candidate items. Candidate items were rated for importance by patient and professional (ENT doctors, general practitioners, microbiologists, nurses, audiologists) stakeholders in a three-round online Delphi exercise. Consensus items were grouped to form the COS, diagnostic criteria, and definition. RESULTS: Candidate COS items from patients (n = 28) and literature (n = 25) were deduplicated and amalgamated to a final candidate list (n = 46). Patients emphasised quality-of-life and the impact on daily activities/work. Via the Delphi process, stakeholders agreed on 31 candidate items. The final COS covered six outcomes: pain; disease severity; impact on quality-of-life and daily activities; patient satisfaction; treatment-related outcome; and microbiology. 14 candidate diagnostic criteria were identified, 8 reaching inclusion consensus. The final definition for AOE was 'diffuse inflammation of the ear canal skin of less than 6 weeks duration'. CONCLUSION: The development and adoption of a consensus definition, diagnostic criteria and a COS will help to standardise future research in AOE, facilitating meta-analysis. Consulting former patients throughout development highlighted deficiencies in the outcomes adopted previously, in particular concerning the impact of AOE on daily life
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