296 research outputs found
Review Paper - High Utility Item sets Mining on Incremental Transactions using UP-Growth and UP-Growth+ Algorithm
One of the important research area in data mining is high utility pattern mining. Discovering itemsets with high utility like profit from database is known as high utility itemset mining. There are number of existing algorithms have been work on this issue. Some of them incurs problem of generating large number of candidate itemsets. This leads to degrade the performance of mining in case of execution time and space. In this paper we have focus on UP-Growth and UP-Growth+ algorithm which overcomes this limitation. This technique uses tree based data structure, UP-Tree for generating candidate itemsets with two scan of database. In this paper we extend the functionality of these algorithms on incremental database.
Transgressions and potential medication errors of nursing students in a simulated environment
Introducción: Los errores de medicación son uno de los eventos de mayor relevancia en la actualidad, derivándose de la interacción entre el medio y los profesionales. La educación debe entrenar a los estudiantes para la seguridad. Objetivo: identificar transgresiones y errores potenciales de medicación en estudiantes de enfermería en los subprocesos de preparación y administración de medicamentos por vía parenteral en ambiente simulado. Método: Estudio cuantitativo, descriptivo realizado en estudiantes de segundo, tercer y cuarto año de la carrera de enfermería de una Universidad chilena. Se evaluaron los subprocesos de preparación y administración a través de la aplicación de una pauta estandarizada de administración segura de medicamentos en ambiente de simulación. Se reconocieron ítems críticos (ítems de transgresiones o errores potenciales) utilizando un punto de corte del 70 %. Resultados: Los estudiantes presentaban edades promedio entre 22 y 24 años, predominando el sexo femenino. Los ítems identificados como críticos en el subproceso de preparación fueron: verificación de la fecha de caducidad del medicamento, transgresión de principios de infecciones asociadas a la atención de salud y preparación de la dosis correcta. En el subproceso de administración se identificó: verificación de alergias, manejo de accesos vasculares, entrega de información e identificación de paciente. Conclusiones: A través de este estudio se identificaron transgresiones y errores potenciales que deben ser trabajados con los estudiantes. La simulación clínica como metodología permite el entrenamiento de competencias orientadas a la provisión de cuidados seguros y de calidad en un ambiente real y protegido
The unconventional myosin CRINKLED and its mammalian orthologue MYO7A regulate caspases in their signalling roles
Caspases provide vital links in non-apoptotic regulatory networks controlling inflammation, compensatory proliferation, morphology and cell migration. How caspases are activated under non-apoptotic conditions and process a selective set of substrates without killing the cell remain enigmatic. Here we find that the Drosophila unconventional myosin CRINKLED (CK) selectively interacts with the initiator caspase DRONC and regulates some of its non-apoptotic functions. Loss of CK in the arista, border cells or proneural clusters of the wing imaginal discs affects DRONC-dependent patterning. Our data indicate that CK acts as substrate adaptor, recruiting SHAGGY46/GSK3-β to DRONC, thereby facilitating caspase-mediated cleavage and localized modulation of kinase activity. Similarly, the mammalian CK counterpart, MYO7A, binds to and impinges on CASPASE-8, revealing a new regulatory axis affecting receptor interacting protein kinase-1 (RIPK1)>CASPASE-8 signalling. Together, our results expose a conserved role for unconventional myosins in transducing caspase-dependent regulation of kinases, allowing them to take part in specific signalling events
CSF1R mosaicism in a family with hereditary diffuse leukoencephalopathy with spheroids
Mutations in the colony stimulating factor 1 receptor
Uteroplacental insufficiency temporally exacerbates salt-induced hypertension associated with a reduced natriuretic response in male rat offspring
Intrauterine growth restriction increases the risk of developing chronic diseases in adulthood. Lifestyle factors, such as poor dietary choices, may elevate this risk. We determined whether being born small increases the sensitivity to a dietary salt challenge, in the context of hypertension, kidney disease and arterial stiffness. Bilateral uterine vessel ligation or sham surgery (offspring termed Restricted and Control, respectively) was performed on 18-day pregnant WKY rats. Male offspring were allocated to receive a diet high in salt (8% sodium chloride) or remain on standard rat chow (0.52% sodium chloride) from 20-26\ua0weeks of age for 6\ua0weeks. Systolic blood pressure (tail-cuff), renal function (24\ua0h urine excretions) and vascular stiffness (pressure myography) were assessed. Restricted males were born 15% lighter than Controls and remained smaller throughout the study. Salt-induced hypertension was exacerbated in Restricted offspring, reaching a peak systolic pressure of ∼175\ua0mmHg earlier than normal weight counterparts. The natriuretic response to high dietary salt in Restricted animals was less than in Controls and may explain the early rise in arterial pressure. Growth restricted males allocated to high salt diet also had increased passive arterial stiffness of mesenteric resistance arteries. Other aspects of renal function, including salt-induced hyperfiltration, albuminuria and glomerular damage were not exacerbated by uteroplacental insufficiency. This study demonstrates that male offspring exposed to uteroplacental insufficiency and born small have an increased sensitivity to salt-induced hypertension and arterial remodelling. This article is protected by copyright. All rights reserved
A cartilage tissue engineering approach combining starch-polycaprolactone fibre mesh scaffolds with bovine articular chondrocytes
In the present work we originally tested the suitability
of corn starch-polycaprolactone (SPCL) scaffolds for
pursuing a cartilage tissue engineering approach. Bovine articular
chondrocytes were seeded on SPCL scaffolds under
dynamic conditions using spinner flasks (total of 4 scaffolds
per spinner flask using cell suspensions of 0.5×106 cells/ml)
and cultured under orbital agitation for a total of 6 weeks.
Poly(glycolic acid) (PGA) non-woven scaffolds and bovine
native articular cartilage were used as standard controls for
the conducted experiments. PGA is a kind of standard in
tissue engineering approaches and it was used as a control
in that sense. The tissue engineered constructs were characterized
at different time periods by scanning electron microscopy
(SEM), hematoxylin-eosin (H&E) and toluidine
blue stainings, immunolocalisation of collagen types I and II,
and dimethylmethylene blue (DMB) assay for glycosaminoglycans
(GAG) quantification assay. SEM results for SPCL
constructs showed that the chondrocytes presented normal
morphological features, with extensive cells presence at the
surface of the support structures, and penetrating the scaffolds
pores. These observations were further corroborated
by H&E staining. Toluidine blue and immunohistochemistry
exhibited extracellular matrix deposition throughout the 3D structure. Glycosaminoglycans, and collagen types I and II
were detected. However, stronger staining for collagen type
II was observed when compared to collagen type I. The PGA
constructs presented similar features toSPCLat the end of the
6 weeks. PGA constructs exhibited higher amounts of matrix
glycosaminoglycans when compared to the SPCL scaffolds.
However, we also observed a lack of tissue in the central
area of the PGA scaffolds. Reasons for these occurrences
may include inefficient cells penetration, necrosis due to high
cell densities, or necrosis related with acidic by-products
degradation. Such situation was not detected in the SPCL
scaffolds, indicating the much better biocompatibility of the
starch based scaffolds
Prospects of micromass culture technology in tissue engineering
Tissue engineering of bone and cartilage tissue for subsequent implantation is of growing interest in cranio- and maxillofacial surgery. Commonly it is performed by using cells coaxed with scaffolds. Recently, there is a controversy concerning the use of artificial scaffolds compared to the use of a natural matrix. Therefore, new approaches called micromass technology have been invented to overcome these problems by avoiding the need for scaffolds. Technically, cells are dissociated and the dispersed cells are then reaggregated into cellular spheres. The micromass technology approach enables investigators to follow tissue formation from single cell sources to organised spheres in a controlled environment. Thus, the inherent fundamentals of tissue engineering are better revealed. Additionally, as the newly formed tissue is devoid of an artificial material, it resembles more closely the in vivo situation. The purpose of this review is to provide an insight into the fundamentals and the technique of micromass cell culture used to study bone tissue engineering
Three-dimensional culture of human meniscal cells: Extracellular matrix and proteoglycan production
<p>Abstract</p> <p>Background</p> <p>The meniscus is a complex tissue whose cell biology has only recently begun to be explored. Published models rely upon initial culture in the presence of added growth factors. The aim of this study was to test a three-dimensional (3D) collagen sponge microenvironment (without added growth factors) for its ability to provide a microenvironment supportive for meniscal cell extracellular matrix (ECM) production, and to test the responsiveness of cells cultured in this manner to transforming growth factor-β (TGF-β).</p> <p>Methods</p> <p>Experimental studies were approved prospectively by the authors' Human Subjects Institutional Review Board. Human meniscal cells were isolated from surgical specimens, established in monolayer culture, seeded into a 3D scaffold, and cell morphology and extracellular matrix components (ECM) evaluated either under control condition or with addition of TGF-β. Outcome variables were evaluation of cultured cell morphology, quantitative measurement of total sulfated proteoglycan production, and immunohistochemical study of the ECM components chondroitin sulfate, keratan sulfate, and types I and II collagen.</p> <p>Result and Conclusion</p> <p>Meniscal cells attached well within the 3D microenvironment and expanded with culture time. The 3D microenvironment was permissive for production of chondroitin sulfate, types I and II collagen, and to a lesser degree keratan sulfate. This microenvironment was also permissive for growth factor responsiveness, as indicated by a significant increase in proteoglycan production when cells were exposed to TGF-β (2.48 μg/ml ± 1.00, mean ± S.D., vs control levels of 1.58 ± 0.79, p < 0.0001). Knowledge of how culture microenvironments influence meniscal cell ECM production is important; the collagen sponge culture methodology provides a useful in vitro tool for study of meniscal cell biology.</p
Activation of JNK Signaling Mediates Amyloid-ß-Dependent Cell Death
Alzheimer's disease (AD) is an age related progressive neurodegenerative disorder. One of the reasons for Alzheimer's neuropathology is the generation of large aggregates of Aß42 that are toxic in nature and induce oxidative stress, aberrant signaling and many other cellular alterations that trigger neuronal cell death. However, the exact mechanisms leading to cell death are not clearly understood.We employed a Drosophila eye model of AD to study how Aß42 causes cell death. Misexpression of higher levels of Aß42 in the differentiating photoreceptors of fly retina rapidly induced aberrant cellular phenotypes and cell death. We found that blocking caspase-dependent cell death initially blocked cell death but did not lead to a significant rescue in the adult eye. However, blocking the levels of c-Jun NH(2)-terminal kinase (JNK) signaling pathway significantly rescued the neurodegeneration phenotype of Aß42 misexpression both in eye imaginal disc as well as the adult eye. Misexpression of Aß42 induced transcriptional upregulation of puckered (puc), a downstream target and functional read out of JNK signaling. Moreover, a three-fold increase in phospho-Jun (activated Jun) protein levels was seen in Aß42 retina as compared to the wild-type retina. When we blocked both caspases and JNK signaling simultaneously in the fly retina, the rescue of the neurodegenerative phenotype is comparable to that caused by blocking JNK signaling pathway alone.Our data suggests that (i) accumulation of Aß42 plaques induces JNK signaling in neurons and (ii) induction of JNK contributes to Aß42 mediated cell death. Therefore, inappropriate JNK activation may indeed be relevant to the AD neuropathology, thus making JNK a key target for AD therapies
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