bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Evaluation of Ceramic Inlays and Onlays Fabricated With Two Systems: Five-Year Follow-Up
Authors: Santos MJ , Mondelli RFL , Navarro MF , Francischone CE , Rubo JH , Santos GC
Published: August 2012

This study evaluated the five-year clinical performance of ceramic inlays and onlays made with two systems: sintered Duceram (Dentsply-Degussa) and pressable IPS Empress (Ivoclar Vivadent). Eighty-six restorations were placed by a single operator in 35 patients with a median age of 33 years. The restorations were cemented with dual-cured resin cement (Variolink II, Ivoclar Vivadent) and Syntac Classic adhesive under rubber dam. The evaluations were conducted by two independent investigators at baseline, and at one, two, three, and five years using the modified United States Public Health Service (USPHS) criteria. At the five-year recall, 26 patients were evaluated (74.28%), totalling 62 (72.09%) restorations. Four IPS restorations were fractured, two restorations presented secondary caries (one from IPS and one from Duceram), and two restorations showed unacceptable defects at the restoration margin and needed replacement (one restoration from each ceramic system). A general success rate of 87% was recorded. The Fisher exact test revealed no significant difference between Duceram and IPS Empress ceramic systems for all aspects evaluated at different recall appointments (p>0.05). The McNemar chi-square test showed significant differences in relation to marginal discoloration, marginal integrity, and surface texture between the baseline and five-year recall for both systems (p<0.001), with an increased percentage of Bravo scores. However, few Charlie or Delta scores were attributed to these restorations. In conclusion, these two types of ceramic materials demonstrated acceptable clinical performance after five years.
Noncarious Cervical Lesions Restored with Three Different Tooth-Colored Materials: Two-Year Results
Authors: Stojanac IL , Premovic MT , Ramic BD , Drobac MR , Stojsin IM , Petrovic LM
Published: August 2012

Introduction:

The aim of this two-year prospective clinical study was to evaluate and compare the clinical performance of three different adhesive esthetic materials in noncarious cervical lesions.

Material and Methods:

A total of 90 restorations (30 per material) were placed in 30 patients who ranged in age between 18 and 50 years and of both genders, by a single operator with no previous preparation. The restoration of noncarious cervical lesions was done with either a microfilled composite (Esthet.X/Dentsply/De Trey, Konstanz, Germany, and Prime&Bond NT/Dentsply/De Trey), a nanohybrid composite (TetricEvoCeram/Vivadent, Schaan, Liechtenstein, and AdheSE/Vivadent), or a compomer (Dyract eXtra/Dentsply/De Trey and Xeno III Dentsply/De Trey). All restorations were evaluated by independent examiners using a modified US Public Health Service criteria at baseline and after 12 and 24 months for six clinical categories. Data were analyzed statistically by Pearson's chi-square or the Fisher's exact test at 5% significance level (p<0.05).

Results:

Results showed that most of the restorations were clinically satisfactory after 12 and 24 months, with no statistically significant differences among the three groups for all evaluated criteria.

Conclusion:

Treatment of noncarious cervical lesions using composite and compomer materials, combined with the appropriate adhesive systems and properly implemented restorative procedures, gives satisfactory results after a two-year evaluation period.
Aeromonas salmonicida infected fish transfer disease to healthy fish via water
Authors: Skrodenytė-Arbačiauskienė Vesta , Kazlauskienė Nijolė , Vosylienė Milda , Virbickas Tomas
Published: August 2012

Experimental studies of infection transmission via water from infected to healthy fish were conducted. The dark-brown bacterial colonies typical for Aeromonas salmonicida on tryptone soya agar (TSA) have been isolated and counted (from 3.0±0.6×102 to 3.5±0.5×105 c.f.u. g−1) from the internal organs of naturally infected (NI) and experimentally infected (EI) perch and sea trout. No significant differences in dark-brown bacterial counts were detected between EI perch and EI sea trout. The assessment and comparison of the alterations of the biological parameters of EI European perch and sea trout with bacterium Aeromonas salmonicida subsp. salmonicida with naturally infected perch were conducted. No mortality was recorded in groups of EI perch and sea trout. Whereas, the mortality of NI perch (collected from the main sites of outbreak of disease) was observed from the second day of the experiments. Changes in morphophysiological parameters of EI perch and sea trout were similar. Different alterations in blood cell parameters of EI fish were observed, and the most noticeable was the decrease (P≤0.01) in white blood cell count (WBC) of EI perch and sea trout. Based on these results it can be deduced that there is infection transmission of bacterium A. salmonicida from European perch via water to other fish species.
Mammalian androgen stimulates photosynthesis in drought-stressed soybean
Authors: Janeczko Anna , Kocurek Maciej , Marcińska Izabela
Published: August 2012

The aim of the present studies was to assess the possibility of compensating the negative effects of drought stress on gaseous exchange and efficiency of photosystem II in soybean seedlings by application of the androgen — androstenedione. Androstenedione (0.25 mg dm−3) was applied via presowing seed soaking (12 h). Control seeds were untreated with steroid. Plants were cultured in pots. On the 12th day of growth, the plants were watered for the last time. Drought symptoms occurred during the next 10 days. On the 22nd day of growth, leaf gaseous exchange and PSII measurements were taken. Afterwards the plants were watered. Two days later measurements were taken again. Androstenedione improved the intensity of leaf net photosynthesis. The effect of androstenedione was manifested during the rehydration of plants that have undergone a period of drought. An increase in net photosynthesis intensity was accompanied by higher transpiration. Possible mechanisms of androstenedione action — effect on aquaporin functionality and membrane stability — are discussed. The significance of ethanol and DMSO (solvents of steroid) in experiments on the physiological activity of androstenedione is also considered.
Analysis of fungal diversity in Orchis tridentata Scopoli
Authors: Pecoraro Lorenzo , Girlanda Mariangela , Kull Tiiu , Perini Claudia , Perotto Silvia
Published: August 2012

We have assessed the identities of fungi associated with Orchis tridentata, an endangered orchid species growing in open woodland and poor grassland of Central and Southern Europe. Fungal diversity in ten O. tridentata adult individuals collected in two protected areas of Central Italy was analysed by means of morphological and molecular methods. Sequencing of the cloned ITS fungal inserts corresponding to the dominant PCR products obtained from amplification of total root DNA with ITS1F and ITS4 primers revealed a variety of fungal species occurring in O. tridentata roots. Among them, members of the basidiomycete families Ceratobasidiaceae, Tulasnellaceae and Hymenogastraceae were recovered, together with ascomycetes belonging to Leptodontidium and Terfezia. The implications of these results in the understanding of O. tridentata biology and for the conservation of this threatened orchid species are discussed.
“Lost sugars” — reality of their biological and medical applications
Authors: Talafová Klaudia , Nahálka Jozef
Published: August 2012

The glycan chains attached to cell surfaces or to single proteins are highly dynamic structures with various functions. The glycan chains of mammals and of some microorganisms often terminate in sialic acids or α-1,3-galactose. Although these two sugars are completely distinct, there are several similarities in their biological and medical importance. First, one type of sialic acid, N-glycolylneuraminic acid, and the galactose bound by an α-1,3-linkage to LacNAc, that forms an α-gal epitope, were both eliminated in human evolution, resulting in the production of antibodies to these sugars. Both of these evolutionary events have consequences connected with the consumption of foods of mammalian origin, causing medical complications of varying severity. In terms of ageing, sialic acids prevent the clearance of glycoproteins and circulating blood cells, whereas cryptic α-gal epitopes on senescent red blood cells contribute to their removal from circulation. The efficiency of therapeutic proteins can be increased by sialylation. Another common feature is the connection with microorganisms since sialic acids and α-gal epitopes serve as receptors on host cells and can also be expressed on the surfaces of some microorganisms. Whereas, the sialylation of IgG antibodies may help to treat inflammation, the expression of the α-gal epitope on microbial antigens increases the immunogenicity of the corresponding vaccines. Finally, sialic acids and the α-gal epitope have applications in cancer immunotherapy. N-glycolylneuraminic acid is a powerful target for cancer immunotherapy, and the α-gal epitope increases the efficiency of cancer vaccines. The final section of this article contains a brief overview of the methods for oligosaccharide chain synthesis and the characteristics of sialyltransferases and α-1,3-galactosyltransferase.
Endozoochorous dispersal of alien and native plants by two palearctic avian frugivores with special emphasis on invasive giant goldenrod Solidago gigantea
Authors: Czarnecka Joanna , Orłowski Grzegorz , Karg Jerzy
Published: August 2012

The role of frugivorous birds in dispersal of the seeds of fleshy-fruited plants is well understood, but other groups of birds like granivores and omnivores can also act as vectors, especially in the process of non-standard dispersal. In this study we examined the role of two widely distributed birds (the Eurasian Blackbird, Turdus merula, and the Black Redstart, Phoenicurus ochruros) in seed dispersal. We analyzed the content of 279 droppings of the Black Redstart collected between July and October and 85 droppings of the Eurasian Blackbird collected during January. In total we found 366 seeds, representing 11 plant taxa, in the faecal samples; 93% of the seeds belonged to fleshy-fruited species. The most numerous were two native taxa, Sambucus racemosa/nigra, in summer and autumn, Crataegus monogyna in winter, and one alien species Morus alba, which is dispersed in summer. We also found seeds of four dry-fruited species; the most interesting of which was the presence of anemochorous seeds of Solidago gigantea (a highly invasive alien species). The seeds were found only in droppings of the Eurasian Blackbird. Considering the obtained results the need for further studies on bird-plant interactions should be a priority.
Vi antigen of Salmonella enetrica serovar Typhi — biosynthesis, regulation and its use as vaccine candidate
Authors: Kaur Jasmine , Jain Swatantra
Published: August 2012

Vi capsular polysaccharide (Vi antigen) was first identified as the virulence antigen of Salmonella enterica serovar Typhi (S. Typhi), the causative agent of typhoid fever in humans. The presence of Vi antigen differentiates S. Typhi from other serovars of Salmonella. Vi antigen is a linear polymer consisting of α-1,4-linked-N-acetyl-galactosaminuronate, whose expression is controlled by three chromosomal loci, namely viaA, viaB and ompB. Both viaA and viaB region are present on Salmonella Pathogenicity Island-7, a large, mosaic, genetic island. The viaA region encodes a positive regulator and the viaB locus is composed of 11 genes designated tviA-tviE (for Vi biosyhthesis), vexA-vexE (for Vi antigen export) and ORF 11. Vi polysaccharide is synthesized from UDP-N-acetyl glucosamine in a series of steps requiring TviB, TviC, and TviE, and regulation of Vi polysaccharide synthesis is controlled by two regulatory systems, rscB-rscC (viaA locus) and ompR-envZ (ompB locus), which respond to changes in osmolarity. This antigen is highly immunogenic and has been used for the formulation of one of the currently available vaccines against typhoid. Despite advancement in the area of vaccinology, its pace of progress needs to be accelerated and effective control programmes will be needed for proper disease management.
Allozyme analysis of Haemonchus contortus resistant and susceptible to anthelmintics, with an indication of dipeptidases associated with resistance
Authors: Šnábel V. , Königová A. , Dolinská M. , Wolstenholme A. , Várady M.
Published: August 2012

In an attempt to investigate the genetic and biochemical causes underlying resistance to anthelmintics, the trichostrongylid nematode Haemonchus contortus was examined by an allozymic analysis of nine candidate geneenzyme systems. Two strains resistant to benzimidazoles, two multidrug-resistant strains, and three strains susceptible to anthelmintics isolated from three continents were examined by isoelectric focusing. Two enzymes (mannose phosphate isomerase and peptidase-D) had polymorphic patterns. The peptidase-D zymograms indicated an association with the selection for resistance. Susceptible isolates gave more complex patterns due to the formation of a heterodimer controlled by the two active loci, whereas in resistant isolates, only a single locus with one electromorph was responsible for the profiles. A possible link between dipeptidases and the acquisition of resistance through the turnover of proteinrich collagen, and changes in membrane-associated genes that influence drug efflux, are discussed.
The use of Nasal Epithelial Stem/progenitor Cells to Produce Functioning Ciliated Cells in vitro
Authors: Zhao Xuening , Yu Fenggang , Li Chunwei , Li Yingying , Chao Siew-Shuen , Loh Woei-Shyang , Pan Xinliang , Shi Li , Wang De-Yun
Published: August 2012

Background

Although epithelial stem/progenitor cells have been isolated from many parts of the human airway epithelium such as lung and trachea, there is limited information in regard to stem cells in nasal epithelium. The aim of this study was to determine if (1) human nasal epithelial stem/progenitor cells (hNESPCs) can be isolated and propagated in vitro and (2) allogeneic adult primary human fibroblasts can serve as a feeder layer for hNESPCs expansion under serum-free conditions.

Methods

Primary cells taken from inferior turbinate biopsy specimens (n = 3) were enzymically dissociated and plated on either allogeneic human fibroblasts or murine NIH 3T3 fibroblasts, in a chemical-defined medium supplemented with growth factors. Self-renewal, proliferation, and differentiation potential were compared.

Results

The optimized media were capable of supporting the undifferentiated growth and expansion of hNESPCs on both feeder cells. The doubling time and cloning efficiency of hNESPCs cultured on a human feeder layer were comparable with that cultured on 3T3 feeders. Significantly, the hNESPCs on both feeder layers could be cultured for four passages, and they can differentiate into ciliated columnar cells and goblet cells at the air–liquid interface, resembling the in vivo mucociliary airway epithelium.

Conclusion

Our results showed the feasibility of expanding hNESPCs for clinical purpose by using human feeder layer, avoiding components of animal source, while preserving their self-renewal and differentiation potential. This study represents an early step toward a better understanding of hNESPCs, and serum -free media plus human feeder potentially would be an ideal method for making clinical grade hNESPCs on a large scale.
Computed Tomographic Evaluation of Pancreatitis and its Complications- Pictoral review
Authors: Ullal S , Joshi KS , Pant P
Published: August 2012

Pancreatitis is one of the commonest pancreatic pathology encountered in day to day clinical practice. Early detection of the entity and its complications can significantly reduce the mortality and morbidity. Various imaging modalities are now available including newer interventional techniques for the diagnosis and therapeutic interventions. For diagnostic purposes, Computed Tomography (CT) has long been regarded as one of the most efficient imaging modalities for evaluation of pancreatitis. This pictoral review is based on Helical CT scans performed in total 50 patients suspicious of having pancreatitis in Kasturba Medical College Hospital, Attavara, Mangalore, India between 2008-2009 and Dhulikhel Hospital, Dhulikhel, Nepal 2010. Various morphological features of both acute and chronic pancreatitis were found on helical CT abdomen. The CT features of acute pancreatitis were focal or diffuse enlargement of pancreas, areas of necrosis, peripancreatic fat strandings, extrapancreatic fluid collections, perinephric fat stranding, perirenal fascial thickening, ascites, pleural effusion, pseudocyst formation etc. The CT features of chronic pancreatitis were focal or diffuse atrophy of the gland, duct dilatation, pancreatic calcifications, ductal calculi etc. Various complications encountered were acute fluid collections, pseudocyst formation, necrosis, pseudoaneurysm, portal vein thrombosis, abscess formation etc. DOI: http://dx.doi.org/10.3126/njms.v1i2.6613 Nepal Journal of Medical Sciences. 2012;1(2): 123-31
Molecular identification of bacteria present in the soils of the Madhupur Sal and the Sunderban mangrove forests of Bangladesh
Authors: Saha Mihir Lal , Islam Mohammad Nurul , Aziz Chaman Binta , Hossain Mohammad Zabed
Published: August 2012

The present study aimed at identifying the soil bacterial communities in the Madhupur Sal and the Sunderban mangrove forests, the two important forests of Bangladesh. Soil bacteria were identified through sequencing of PCR?amplified fragments of bacterial 16S rDNA. The results showed that the bacterial communities of the Madhupur Sal forest soils and that of the Sunderban mangrove forest soils differed in the morphology of the cells. Data presented here also showed that the bacterial communities of the Sunderban mangrove forest soils were more diverse than that of the Madhupur Sal forest soils as revealed by phylogenetic tree analysis of the 16S rDNA sequences.DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11509Dhaka Univ. J. Biol. Sci. 21(2): 117?123, 2012 (July)
Morphology and biology of the bedbug, Cimex hemipterus (Hemiptera: Cimicidae) in the laboratory
Authors: Khan Humuayun Reza , Rahman Md Monsur
Published: August 2012

Adult bedbugs collected from Fazlul Huq Muslim Hall, University of Dhaka were identified as Cimex hemipterus Fabricius (Hemiptera: Cimicidae). The bedbug species was reared and its morphology and biology were studied in the laboratory at room temperature 28 ± 4ºC and 70 ± 10% RH. The average incubation period of the eggs was 7.67 ± 2.08 days. Average nymphal duration was 53.67 ± 2.52 days. The five stadia (stage durations) of the five nymphs were 8.33 ± 0.58, 12.0 ± 1.0, 11.33 ± 0.58, 12.0 ± 1.0 and 10.0 ± 1.0 days, respectively. Average time required from egg laying to adult emergence was 61.67 ± 3.21 days.DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11510 Dhaka Univ. J. Biol. Sci. 21(2): 125-130, 2012 (July)
Prevalence and intensity of parasites in domestic ducks
Authors: Musa Sharmin , Rahman Tania , Khanum Hamida
Published: August 2012

DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11518Dhaka Univ. J. Biol. Sci. 21(2): 197-199, 2012 (July)
Characterization of some representative soils from the Ganges floodplain of Bangladesh
Authors: Hasan MK , Mohiuddin ASM , Uddin MJ
Published: August 2012

DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11519Dhaka Univ. J. Biol. Sci. 21(2): 201-205, 2012 (July)
Autophagy During Vertebrate Development
Authors: Aburto María R. , Hurlé Juan M. , Varela-Nieto Isabel , Magariños Marta
Published: August 2012

Autophagy is an evolutionarily conserved catabolic process by which cells degrade their own components through the lysosomal machinery. In physiological conditions, the mechanism is tightly regulated and contributes to maintain a balance between synthesis and degradation in cells undergoing intense metabolic activities. Autophagy is associated with major tissue remodeling processes occurring through the embryonic, fetal and early postnatal periods of vertebrates. Here we survey current information implicating autophagy in cellular death, proliferation or differentiation in developing vertebrates. In developing systems, activation of the autophagic machinery could promote different outcomes depending on the cellular context. Autophagy is thus an extraordinary tool for the developing organs and tissues.
Impact of Interference in Coexisting Wireless Networks with Applications to Arbitrarily Varying Bidirectional Broadcast Channels
Authors: Wyrembelski Rafael F. , Boche Holger
Published: August 2012

The paradigm shift from an exclusive allocation of frequency bands, one for each system, to a shared use of frequencies comes along with the need of new concepts since interference will be an ubiquitous phenomenon. In this paper, we use the concept of arbitrarily varying channels to model the impact of unknown interference caused by coexisting wireless systems which operate on the same frequencies. Within this framework, capacity can be zero if pre-specified encoders and decoders are used. This necessitates the use of more sophisticated coordination schemes where the choice of encoders and decoders is additionally coordinated based on common randomness. As an application we study the arbitrarily varying bidirectional broadcast channel and derive the capacity regions for different coordination strategies. This problem is motivated by decode-and-forward bidirectional or two-way relaying, where a relay establishes a bidirectional communication between two other nodes while sharing the resources with other coexisting wireless networks.
On the Efficiency of a Two-Power-Level Flywheel-Based All-Electric Driveline
Authors: Abrahamsson Johan , De Oliveira Janaína Gonçalves , De Santiago Juan , Lundin Johan , Bernhoff Hans
Published: August 2012

This paper presents experimental results on an innovative electric driveline employing a kinetic energy storage device as energy buffer. A conceptual division of losses in the system was created, separating the complete system into three parts according to their function. This conceptualization of the system yielded a meaningful definition of the concept of efficiency. Additionally, a thorough theoretical framework for the prediction of losses associated with energy storage and transfer in the system was developed. A large number of spin-down tests at varying pressure levels were performed. A separation of the measured data into the different physical processes responsible for power loss was achieved from the corresponding dependence on rotational velocity. This comparison yielded an estimate of the perpendicular resistivity of the stranded copper conductor of 2.5 × 10−8 ± 3.5 × 10−9. Further, power and energy were measured system-wide during operation, and an analysis of the losses was performed. The analytical solution was able to reproduce the measured distribution of losses in the system to an accuracy of 4.7% (95% CI). It was found that the losses attributed to the function of kinetic energy storage in the system amounted to between 45% and 65%, depending on usage.
A Model of Evolution of Development Based on Germline Penetration of New “No-Junk” DNA
Authors: Fontana Alessandro , Wróbel Borys
Published: August 2012

There is a mounting body of evidence that somatic transposition may be involved in normal development of multicellular organisms and in pathology, especially cancer. Epigenetic Tracking (ET) is an abstract model of multicellular development, able to generate complex 3-dimensional structures. Its aim is not to model the development of a particular organism nor to merely summarise mainstream knowledge on genetic regulation of development. Rather, the goal of ET is to provide a theoretical framework to test new postulated genetic mechanisms, not fully established yet in mainstream biology. The first proposal is that development is orchestrated through a subset of cells which we call driver cells. In these cells, the cellular state determines a specific pattern of gene activation which leads to the occurrence of developmental events. The second proposal is that evolution of development is affected by somatic transposition events. We postulate that when the genome of a driver cell does not specify what developmental event should be undertaken when the cell is in a particular cellular state, somatic transposition events can reshape the genome, build new regulatory regions, and lead to a new pattern of gene activation in the cell. Our third hypothesis, not supported yet by direct evidence, but consistent with some experimental observations, is that these new “no-junk” sequences—regulatory regions created by transposable elements at new positions in the genome—can exit the cell and enter the germline, to be incorporated in the genome of the progeny. We call this mechanism germline penetration. This process allows heritable incorporation of novel developmental events in the developmental trajectory. In this paper we will present the model and link these three postulated mechanisms to biological observations.
Evaluation of Sex-Specific Gene Expression in Archived Dried Blood Spots (DBS)
Authors: Resau James H. , Ho Nhan T. , Dykema Karl , Faber Matthew S. , Busik Julia V. , Nickolov Radoslav Z. , Furge Kyle A. , Paneth Nigel , Jewell Scott , Khoo Sok Kean
Published: August 2012

Screening newborns for treatable serious conditions is mandated in all US states and many other countries. After screening, Guthrie cards with residual blood (whole spots or portions of spots) are typically stored at ambient temperature in many facilities. The potential of archived dried blood spots (DBS) for at-birth molecular studies in epidemiological and clinical research is substantial. However, it is also challenging as analytes from DBS may be degraded due to preparation and storage conditions. We previously reported an improved assay for obtaining global RNA gene expression from blood spots. Here, we evaluated sex-specific gene expression and its preservation in DBS using oligonucleotide microarray technology. We found X inactivation-specific transcript (XIST), lysine-specific demethylase 5D (KDM5D) (also known as selected cDNA on Y, homolog of mouse (SMCY)), uncharacterized LOC729444 (LOC729444), and testis-specific transcript, Y-linked 21 (TTTY21) to be differentially-expressed by sex of the newborn. Our finding that trait-specific RNA gene expression is preserved in unfrozen DBS, demonstrates the technical feasibility of performing molecular genetic profiling using such samples. With millions of DBS potentially available for research, we see new opportunities in using newborn molecular gene expression to better understand molecular pathogenesis of perinatal diseases.
Isolation and Identification of Fourteen Microsatellite Markers in Clivia miniata and Clivia nobilis (Amaryllidaceae)
Authors: Gao Wei , Zhao He , Liu Ying , Li Ming-Rui , Nurmamat Eliyas , Li Lin-Feng , Ren Yue-Ying , Xiao Hong-Xing
Published: August 2012

Clivia is a genus of great horticultural importance and has been widely cultivated as ornamental plants in all over the world. In order to assess the phylogenetic relationships and genetic diversity of the wild Clivia species and cultivars, we isolated AC-enriched repeats using FIASCO from a single clone each of C. miniata Regel. and Clivia nobilis Lindl. Of the fourteen repeats, 10 were polymorphic and 4 were monomorphic. The polymorphic marker loci were characterized using 61 Clivia accessions. The number of alleles ranged from two to six, observed heterozygosity ranged from 0.04 to 1.00 and expected heterozygosity ranged from 0.04 to 0.83. These microsatellite marker loci provide tools for future studies of Clivia species and cultivars.
Arsenic Trioxide Inhibits Cell Growth and Induces Apoptosis through Inactivation of Notch Signaling Pathway in Breast Cancer
Authors: Xia Jun , Li Youjian , Yang Qingling , Mei Chuanzhong , Chen Zhiwen , Bao Bin , Ahmad Aamir , Miele Lucio , Sarkar Fazlul H , Wang Zhiwei
Published: August 2012

Arsenic trioxide has been reported to inhibit cell growth and induce apoptotic cell death in many human cancer cells including breast cancer. However, the precise molecular mechanisms underlying the anti-tumor activity of arsenic trioxide are still largely unknown. In the present study, we assessed the effects of arsenic trioxide on cell viability and apoptosis in breast cancer cells. For mechanistic studies, we used multiple cellular and molecular approaches such as MTT assay, apoptosis ELISA assay, gene transfection, RT-PCR, Western blotting, and invasion assays. For the first time, we found a significant reduction in cell viability in arsenic trioxide-treated cells in a dose-dependent manner, which was consistent with induction of apoptosis and also associated with down-regulation of Notch-1 and its target genes. Taken together, our findings provide evidence showing that the down-regulation of Notch-1 by arsenic trioxide could be an effective approach, to cause down-regulation of Bcl-2, and NF-κB, resulting in the inhibition of cell growth and invasion as well as induction of apoptosis. These results suggest that the anti-tumor activity of arsenic trioxide is in part mediated through a novel mechanism involving inactivation of Notch-1 and its target genes. We also suggest that arsenic trioxide could be further developed as a potential therapeutic agent for the treatment of breast cancer.
Silica as a Matrix for Encapsulating Proteins: Surface Effects on Protein Structure Assessed by Circular Dichroism Spectroscopy
Authors: Calabretta Phillip J. , Chancellor Mitchell C. , Torres Carlos , Abel Gary R. , Niehaus Clayton , Birtwhistle Nathan J. , Khouderchah Nada M. , Zemede Genet H. , Eggers Daryl K.
Published: August 2012

The encapsulation of biomolecules in solid materials that retain the native properties of the molecule is a desired feature for the development of biosensors and biocatalysts. In the current study, protein entrapment in silica-based materials is explored using the sol-gel technique. This work surveys the effects of silica confinement on the structure of several model polypeptides, including apomyoglobin, copper-zinc superoxide dismutase, polyglutamine, polylysine, and type I antifreeze protein. Changes in the secondary structure of each protein following encapsulation are monitored by circular dichroism spectroscopy. In many cases, silica confinement reduces the fraction of properly-folded protein relative to solution, but addition of a secondary solute or modification of the silica surface leads to an increase in structure. Refinement of the glass surface by addition of a monosubstituted alkoxysilane during sol-gel processing is shown to be a valuable tool for testing the effects of surface chemistry on protein structure. Because silica entrapment prevents protein aggregation by isolating individual protein molecules in the pores of the glass material, one may monitor aggregation-prone polypeptides under solvent conditions that are prohibited in solution, as demonstrated with polyglutamine and a disease-related variant of superoxide dismutase.
Ursolic Acid Inhibits Cigarette Smoke Extract-Induced Human Bronchial Epithelial Cell Injury and Prevents Development of Lung Cancer
Authors: Liu Wenbo , Tan Xiaobin , Shu Luan , Sun Hanyan , Song Jie , Jin Ping , Yu Siming , Sun Min , Jia Xiaobin
Published: August 2012

Cigarette smoking is the main cause of chronic obstructive pulmonary disease and lung cancer. The present study was aimed to explore the chemopreventive effect of ursolic acid (UA) on these diseases. In the CSE treated normal human bronchial epithelial cell model, UA alleviated cytotoxicity caused by CSE, recovered the intracellular redox balance, and relieved the stimulation of external deleterious factors as well. UA mitigated CSE-induced DNA damage through the Nrf2 (nuclear factor erythroid 2-related factor 2) pathway. Moreover, UA inhibited lung cancer development in the model established by A549 cells in nude mice in vivo. For the first time, our results indicate that UA could be developed as a potential lung cancer chemopreventive agent.
Protective Effects of Chlorella-Derived Peptide Against UVC-Induced Cytotoxicity through Inhibition of Caspase-3 Activity and Reduction of the Expression of Phosphorylated FADD and Cleaved PARP-1 in Skin Fibroblasts
Authors: Shih Mei Fen , Cherng Jong Yuh
Published: August 2012

UVC irradiation induces oxidative stress and leads to cell death through an apoptotic pathway. This apoptosis is caused by activation of caspase-3 and formation of poly(ADP-ribose) polymerase-1 (PARP-1). In this study, the underlying mechanisms of Chlorella derived peptide (CDP) activity against UVC-induced cytotoxicity were investigated. Human skin fibroblasts were treated with CDP, vitamin C, or vitamin E after UVC irradiation for a total energy of 15 J/cm2. After the UVC exposure, cell proliferation and caspase-3 activity were measured at 12, 24, 48, and 72 h later. Expression of phosphorylated FADD and cleaved PARP-1 were measured 16 h later. DNA damage (expressed as pyrimidine (6-4) pyrimidone photoproducts DNA concentration) and fragmentation assay were performed 24 h after the UVC exposure. Results showed that UVC irradiation induced cytotoxicity in all groups except those treated with CDP. The caspase-3 activity in CDP-treated cells was inhibited from 12 h onward. Expression of phosphorylated FADD and cleaved PARP-1 were also reduced in CDP-treated cells. Moreover, UVC-induced DNA damage and fragmentation were also prevented by the CDP treatment. This study shows that treatment of CDP provides protective effects against UVC-induced cytotoxicity through the inhibition of caspase-3 activity and the reduction of phosphorylated FADD and cleaved PARP-1 expression.
Bioactivities of the Genus Combretum (Combretaceae): A Review
Authors: De  Morais Lima Gedson Rodrigues , De Sales Igor Rafael Praxedes , Caldas Filho Marcelo Ricardo Dutra , De Jesus Neyres Zínia Taveira , De Sousa Falcão Heloina , Barbosa-Filho José Maria , Cabral Analúcia Guedes Silveira , Souto Augusto Lopes , Tavares Josean Fechine , Batista Leônia Maria
Published: August 2012

The Combretaceae is a large family of herbs, shrubs and trees, comprising about 20 genera and 600 species with tropical distribution around the globe and centers of diversity in Africa and Asia. Some Combretum species are extensively used in traditional medicine against inflammation, infections, diabetes, malaria, bleeding, diarrhea and digestive disorders and others as a diuretic. The present work is a literature survey of Combretum species that have been evaluated for their ability to exert biological activities. A total number of 36 Combretum species are discussed with regard to plant parts used, component tested and bioassay models. This review is of fundamental importance to promoting studies on Combretum species, thereby contributing to the development of new therapeutic alternatives that may improve the health of people suffering from various health problems.
Real Time Anti-Toxoplasma gondii Activity of an Active Fraction of Eurycoma longifolia Root Studied by in Situ Scanning and Transmission Electron Microscopy
Authors: Kavitha Nowroji , Noordin Rahmah , Kit-Lam Chan , Sasidharan Sreenivasan
Published: August 2012

The inhibitory effect of active fractions of Eurycoma longifolia (E. longifolia) root, namely TAF355 and TAF401, were evaluated against Toxoplasma gondii (T. gondii). In our previous study, we demonstrated that T. gondii was susceptible to TAF355 and TAF401 with IC50 values of 1.125 µg/mL and 1.375 µg/mL, respectively. Transmission (TEM) and scanning electron microscopy (SEM) observations were used to study the in situ antiparasitic activity at the IC50 value. Clindamycin was used as positive control. SEM examination revealed cell wall alterations with formation of invaginations followed by completely collapsed cells compared to the normal T. gondii cells in response to the fractions. The main abnormality noted via TEM study was decreased cytoplasmic volume, leaving a state of structural disorganization within the cell cytoplasm and destruction of its organelles as early as 12 h of treatment, which indicated of rapid antiparasitic activity of the E. longifolia fractions. The significant antiparasitic activity shown by the TAF355 and TAF401 active fractions of E. longifolia suggests their potential as new anti-T. gondii agent candidates.
Influences of Dryopteris crassirhizoma Extract on the Viability, Growth and Virulence Properties of Streptococcus mutans
Authors: Ban Suk-Ho , Kim Jeong-Eun , Pandit Santosh , Jeon Jae-Gyu
Published: August 2012

Dryopteris crassirhizoma is traditionally used as an herbal remedy for various diseases, and has been identified in a previous study as a potential anti-caries agent. In this study, the effect of a methanol extract of D. crassirhizoma on the viability, growth and virulence properties of Streptococcus mutans, a cariogenic dental pathogen, was investigated. In addition, the phytochemical composition of the extract was analyzed. The extract showed bactericidal and bacteriostatic activity against oral bacteria (MIC and MBC of S. mutans: 62.5 and 250 μg/mL, respectively). At two times the MBC, the extract significantly eliminated S. mutans up to 99.9% after 1 h incubation. The extract also dose-dependently reduced growth rates of S. mutans at sub-MIC levels. Furthermore, at sub-MIC levels, virulence properties (acid production, acid tolerance, glucosyltransferase activity and sucrose-dependent adherence) of S. mutans were also inhibited in a dose-dependent manner. GC-MS analysis revealed the presence of mono and disaccharides (44.9%), fatty acids (12.3%) and sugar alcohols (6.8%) in the extract. These data indicate that the extract might be useful for the control of dental caries.
3-Phenylcoumarins as Inhibitors of HIV-1 Replication
Authors: Olmedo Dionisio , Sancho Rocío , Bedoya Luis M. , López-Pérez José L. , Del Olmo Esther , Muñoz Eduardo , Alcamí José , Gupta Mahabir P. , San Feliciano Arturo
Published: August 2012

We have synthesized fourteen 3-phenylcoumarin derivatives and evaluated their anti-HIV activity. Antiviral activity was assessed on MT-2 cells infected with viral clones carrying the luciferase gene as reporter. Inhibition of HIV transcription and Tat function were tested on cells stably transfected with the HIV-LTR and Tat protein. Six compounds displayed NF-κB inhibition, four resulted Tat antagonists and three of them showed both activities. Three compounds inhibited HIV replication with IC50 values < 25 µM. The antiviral effect of the 4-hydroxycoumarin derivative 19 correlates with its specific inhibition of Tat functions, while compound 8, 3-(2-chlorophenyl)coumarin, seems to act through a mechanism unrelated to the molecular targets considered in this research.
Chemical Genetics: Budding Yeast as a Platform for Drug Discovery and Mapping of Genetic Pathways
Authors: Enserink Jorrit M.
Published: August 2012

The budding yeast Saccharomyces cerevisiae is a widely used model organism, and yeast genetic methods are powerful tools for discovery of novel functions of genes. Recent advancements in chemical-genetics and chemical-genomics have opened new avenues for development of clinically relevant drug treatments. Systematic mapping of genetic networks by high-throughput chemical-genetic screens have given extensive insight in connections between genetic pathways. Here, I review some of the recent developments in chemical-genetic techniques in budding yeast.
Mechanisms for the Direct Electron Transfer of Cytochrome c Induced by Multi-Walled Carbon Nanotubes
Authors: Zhao Hua-Zhang , Du Qian , Li Zhen-Shan , Yang Qin-Zheng
Published: August 2012

Multi-walled carbon nanotube (MWCNT)-modified electrodes can promote the direct electron transfer (DET) of cytochrome c (Cyt c). There are several possible mechanisms that explain the DET of Cyt c. In this study, several experimental methods, including Fourier transform infrared spectroscopy, circular dichroism, ultraviolet-visible absorption spectroscopy, and electron paramagnetic resonance spectroscopy were utilized to investigate the conformational changes of Cyt c induced by MWCNTs. The DET mechanism was demonstrated at various nano-levels: secondary structure, spatial orientation, and spin state. In the presence of MWCNTs, the secondary structure of Cyt c changes, which exposes the active site, then, the orientation of the heme is optimized, revolving the exposed active center to the optimum spatial orientation for DET; and finally, a transition of spin states is induced, providing relatively high energy and a more open microenvironment for electron transfer. These changes at different nano-levels are closely connected and form a complex process that promotes the electron transfer of Cyt c.
Cross Layer Adaptation of Check Intervals in Low Power Listening MAC Protocols for Lifetime Improvement in Wireless Sensor Networks
Authors: Escolar Soledad , Chessa Stefano , Carretero Jesús , Marinescu Maria-Cristina
Published: August 2012

Preamble sampling-based MAC protocols designed forWireless Sensor Networks (WSN) are aimed at prolonging the lifetime of the nodes by scheduling their times of activity. This scheduling exploits node synchronization to find the right trade-off between energy consumption and delay. In this paper we consider the problem of node synchronization in preamble sampling protocols. We propose Cross Layer Adaptation of Check intervals (CLAC), a novel protocol intended to reduce the energy consumption of the nodes without significantly increasing the delay. Our protocol modifies the scheduling of the nodes based on estimating the delay experienced by a packet that travels along a multi-hop path. CLAC uses routing and MAC layer information to compute a delay that matches the packet arrival time. We have implemented CLAC on top of well-known routing and MAC protocols for WSN, and we have evaluated our implementation using the Avrora simulator. The simulation results confirm that CLAC improves the network lifetime at no additional packet loss and without affecting the end-to-end delay.
Renal Replacement Therapy in Congestive Heart Failure Requiring Left Ventricular Assist Device Augmentation
Authors: Thomas Bernadette A. , Logar Christine M. , Anderson Arthur E.
Published: August 2012

“Cardiorenal syndrome” is a term used to describe a dysregulation of the heart affecting the kidneys, or vice versa, in an acute or chronic manner ( 1 , 2 ). Renal impairment can range from reversible ischemic damage to renal failure requiring short- or long-term renal replacement therapy ( 2 ). Patients who require mechanical circulatory support, such as a left ventricular assist device (LVAD), as definitive treatment for congestive heart failure or as a bridge to cardiac transplantation pose a unique challenge with respect to receiving dialysis, because they experience higher rates of morbidity and mortality from infection in the post-LVAD period ( 3 - 7 ). Acute dialysis access can pose an increased infection risk.

In this article, we present a patient who required renal replacement therapy and a LVAD for management of acute-on-chronic cardiorenal syndrome while awaiting heart transplantation. A literature review to determine whether peritoneal dialysis or hemodialysis is superior for patients with profound hemodynamic dysfunction and the need to minimize risk of infection did not offer clear guidance about which modality is superior in patients with advanced congestive heart failure. However, there is clear evidence of the superiority of peritoneal dialysis in reducing the risk of systemic infection secondary to acute dialysis access. Given the high risk of LVAD infection, we therefore conclude that, to decrease mortality secondary to systemic infection, peritoneal dialysis should strongly be considered in patients who require renal replacement therapy before or after LVAD placement.
Risk Factors and Consequences of Hyperaluminemia in a Peritoneal Dialysis Cohort
Authors: Lavergne Valery , Ghannoum Marc , Christie Megan , Vo Van , Tam Paul W. , Ting Robert , Sikaneta Tabo
Published: August 2012

♦ Background

Widespread Al toxicity is unusual today. In 2005, Canadian peritoneal dialysis (PD) centers reported widespread hyperaluminemia in patients using dialysates from one specific manufacturer. Our objectives were to evaluate risk factors related to Al accumulation and to assess its clinical consequences in patients from 2 centers.

♦ Methods

A retrospective closed cohort study was conducted in patients treated with PD in May 2005. A multivariate linear regression model was constructed to identify variables associated with a higher serum Al level in the exposed group at the moment of solution change. Using appropriate statistical methods, anemia and bone metabolism parameters were compared between the exposed and unexposed groups. Time to first peritonitis was estimated by the Kaplan–Meier method.

♦ Results

The study cohort included 87 Al-exposed patients and 95 unexposed patients. In the exposed group, serum Al at the moment of solution change was influenced by the length of exposure to Al-containing dialysates and by PD creatinine clearance; serum Al was inversely correlated with renal creatinine clearance. No consequences of Al accumulation were observed. No difference was observed in the time to first peritonitis between patients who switched manufacturers and those who remained with the original manufacturer.

♦ Conclusions

Our results suggest that hyperaluminemia is directly related to the length and extent of exposure to Al-containing dialysates; residual renal function is protective against Al accumulation. Because the problem was detected rapidly, no clinical consequences of hyperaluminemia were observed in the study cohort.
Clinical Characteristics and Outcomes of “Silent” and “Non-Silent” Peritonitis in Patients on Peritoneal Dialysis
Authors: Dong Jie , Luo Suping , Xu Rong , Chen Yuan , Xu Ying
Published: August 2012

♦Objectives

We compared the clinical characteristics and outcomes of “silent” peritonitis (meaning episodes without fever and abdominal pain) and “non-silent” peritonitis in patients on peritoneal dialysis (PD).

♦Methods

Our cohort study collected data about all peritonitis episodes occurring between January 2008 and April 2010. Disease severity score, demographics, and biochemistry and nutrition data were recorded at baseline. Effluent cell counts were examined at regular intervals, and the organisms cultured were examined. Treatment failure was defined as peritonitis-associated death or transfer to hemodialysis.

♦Results

Of 248 episodes of peritonitis occurring in 161 PD patients, 20.9% led to treatment failure. Of the 248 episodes, 51 (20.6%) were not accompanied by fever and abdominal pain. Patients with these silent peritonitis episodes tended to be older ( p = 0.003). The baseline values for body mass index, triglycerides, and daily energy intake were significantly lower before silent peritonitis episodes than before non-silent episodes ( p = 0.01, 0.003, and 0.001 respectively). Although silent peritonitis episodes were more often culture-negative and less often caused by gram-negative organisms, and although they presented with low effluent white cell counts on days 1 and 3, the risk for treatment failure in those episodes was not lower (adjusted odds ratio: 1.33; 95% confidence interval: 0.75 to 2.36; p = 0.33).

♦Conclusions

Silent peritonitis is not a rare phenomenon, especially in older patients on PD. Although these episodes were more often culture-negative, silent presentation was not associated with a better outcome.