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1.
Int J Organ Transplant Med ; 11(3): 95-100, 2020.
Article En | MEDLINE | ID: mdl-32913584

BACKGROUND: Patients with end-stage renal disease (ESRD) undergo a transition of care between their primary nephrologist and the transplant center during evaluation for kidney transplantation. Due to medical complexity, high hospitalization rate, and involvement of multiple medical stakeholders, transitions of medical care among patients with ESRD are likely to be associated with suboptimal care and medical errors. Provider-to-provider communication improves outcomes among ESRD patients transitioning between dialysis and transplant. There is little data analyzing proper transition of care between the nephrologist and the transplant center (TC). OBJECTIVE: Using survey methodology, we examined nephrologists' current practice and experience regarding patient-related communication with the TC. METHODS: From among 822 nephrologists who were following at least 20 ESRD patients, we randomly selected 252 nephrologists to participate in the study. The survey consisted of 102 multiple choice and Likert-style items probing perceptions about various aspects of transplant, including communication between TC and nephrologist. Responses from 216 participants who submitted complete responses were included in the final analysis. RESULTS: Depending on the phase of transplant, nephrologist-TC communication varied between 50%-81% of nephrologists. Factors associated with higher likelihood of nephrologist-TC communication included attending transplant-related educational activity, practicing in a group with more than 5 nephrologists, and having more than 50 patients on dialysis. The majority of nephrologists indicated satisfaction with access to an attending physician in the TC, receiving timely and adequate information from the TC about their patients. Factors associated with higher likelihood of nephrologist satisfaction regarding communication with the TC included attending national nephrology meetings, medical directorship of a dialysis unit, fellowship training at an institution with an on-site transplant program, and availability of more than 2 transplant centers within 50 miles. CONCLUSION: There is a lack of evidence-based guidelines for patient transfer of care between nephrologists and transplant centers during various phases of transplant referral, evaluation and post-transplant care. We found that the likelihood of the nephrologists' communication with the transplant center and their satisfaction with the communication are related to their training, participation in continuing educational meetings, their practice location and size, and the overall composition of their patient population.

2.
Int J Organ Transplant Med ; 10(3): 101-107, 2019.
Article En | MEDLINE | ID: mdl-31497272

BACKGROUND: Provider perceptions about patient candidacy for kidney transplant (KT) are potentially significant contributors to disparities in KT. OBJECTIVE: To examine nephrologists' perceptions about factors that are important in excluding patients from KT referral, and to analyze the association between these perceptions and nephrologists' demographic and practice characteristics.Methods: Invitations were sent to 3180 nephrologists. Among those who consented, 822 fulfilled the inclusion criteria, and 250 were randomly invited to complete a questionnaire about perceptions of factors essential in deciding not to refer patients for KT. RESULTS: Responses from 216 participants with complete responses were analyzed. The 3 most common reasons for excluding patients were "patient's inadequate social support" (44%), "limited understanding of the process due to patient's inadequate education" (32%), and "patient's age above 65" (26%). Nephrologists practicing in rural settings were more likely to consider inadequate support and limited education of patients as reasons not to refer for KT. In multivariate analysis, physicians with 2 or fewer transplant centers within 50 miles were more likely to report inadequate social support (OR: 3.15, 95% CI: 1.59-6.24) and age greater than 65 years (OR: 1.88, 95% CI: 1.01-3.49) as reasons to exclude patients from KT referral. Nephrologists whose practice included patients majority of whom had not completed high school were more likely to consider limited understanding due to inadequate education as an important reason to exclude patients from KT (OR: 3.31, 95% CI: 1.60-6.86). CONCLUSION: Patient's social support, understanding, and age were the most common factors regarded by nephrologists as important in not referring patients for KT evaluation. Practice location, particularly rural setting, proximity to a transplant center, and the education level of a nephrologist's patient population were important determinants of referral for KT.

3.
Biochemistry (Mosc) ; 83(4): 402-410, 2018 Apr.
Article En | MEDLINE | ID: mdl-29626927

Chromosomal translocations have long been known for their association with malignant transformation, particularly in hematopoietic disorders such as B-cell lymphomas. In addition to the physiological process of maturation, which creates double strand breaks in immunoglobulin gene loci, environmental factors including the Epstein-Barr and human immunodeficiency viruses, malaria-causing parasites (Plasmodium falciparum), and plant components (Euphorbia tirucalli latex) can trigger a reorganization of the nuclear architecture and DNA damage that together will facilitate the occurrence of deleterious chromosomal rearrangements.


B-Lymphocytes/metabolism , B-Lymphocytes/pathology , Cell Transformation, Neoplastic , Translocation, Genetic/genetics , DNA Damage , Euphorbia/metabolism , HIV/metabolism , Herpesvirus 4, Human/metabolism , Humans , Plasmodium falciparum/metabolism
4.
Leukemia ; 31(11): 2515-2522, 2017 11.
Article En | MEDLINE | ID: mdl-28360415

With combined antiretroviral therapy (cART), the risk for HIV-infected individuals to develop a non-Hodgkin lymphoma is diminished. However, the incidence of Burkitt lymphoma (BL) remains strikingly elevated. Most BL present a t(8;14) chromosomal translocation which must take place at a time of spatial proximity between the translocation partners. The two partner genes, MYC and IGH, were found colocalized only very rarely in the nuclei of normal peripheral blood B-cells examined using 3D-FISH while circulating B-cells from HIV-infected individuals whose exhibited consistently elevated levels of MYC-IGH colocalization. In vitro, incubating normal B-cells from healthy donors with a transcriptionally active form of the HIV-encoded Tat protein rapidly activated transcription of the nuclease-encoding RAG1 gene. This created DNA damage, including in the MYC gene locus which then moved towards the center of the nucleus where it sustainably colocalized with IGH up to 10-fold more frequently than in controls. In vivo, this could be sufficient to account for the elevated risk of BL-specific chromosomal translocations which would occur following DNA double strand breaks triggered by AID in secondary lymph nodes at the final stage of immunoglobulin gene maturation. New therapeutic attitudes can be envisioned to prevent BL in this high risk group.


B-Lymphocytes/metabolism , Burkitt Lymphoma/genetics , Gene Products, tat/physiology , Genes, myc , Immunoglobulin Heavy Chains/genetics , Aged , Female , Humans , Male , Middle Aged
5.
Biogerontology ; 18(4): 535-548, 2017 08.
Article En | MEDLINE | ID: mdl-28316011

Mechanisms underpinning age-related decreases in muscle strength and muscle mass relate to chronic inflammation. Physical activity induces an anti-inflammatory effect, but it is modulated by additional factors. We hypothesized that vitamin D, which has also anti-inflammatory activity will modify adaptation to exercise and reduce inflammation in elderly women. Twenty-seven women aged 67 ± 8 years were included and divided into groups with baseline vitamin D concentration more than 20 ng mL-1 (MVD) and less than 20 ng mL-1 (LVD). Both groups performed 1 h Nordic Walking (NW) training combined with vitamin D supplementation for 12 weeks. Serum concentrations of inflammation markers, branched amino acids, vitamin D, muscle strength and balance were assessed at the baseline and three days after intervention. The training caused the significant decrease in concentration of pro-inflammatory proteins HMGB1 (30 ± 156%; 90% CI) and IL-6 (-10 ± 66%; 90% CI) in MVD group. This effects in group MVD were moderate, indicating vitamin D as one of the modifiers of these exercise-induced changes. Rise of myokine irisin induced by exercise correlated inversely with HMGB1 and the correlation was more pronounced at the baseline as well as after training among MVD participants. Although the intervention caused the leucine level to rise, a comparison of the recorded response between groups and the adjusted effect indicated that the effect was 20% lower in the LVD group. Overall the applied training program was effective in reducing HMGB1 concentration. This drop was accompanied by the rise of myokine irisin and better uptake of leucine among women with higher baseline vitamin D.


Aging/blood , Cholecalciferol/therapeutic use , Dietary Supplements , Exercise Therapy/methods , Healthy Aging/blood , Inflammation Mediators/blood , Leucine/blood , Walking , Age Factors , Aged , Cholecalciferol/blood , Female , HMGB1 Protein/blood , Humans , Interleukin-6/blood , Middle Aged , Muscle Strength , Poland , Postural Balance , Sex Factors , Time Factors , Treatment Outcome
6.
Biochemistry (Mosc) ; 81(7): 678-90, 2016 Jul.
Article En | MEDLINE | ID: mdl-27449614

Muscular dystrophies are a group of heterogeneous genetic disorders characterized by progressive loss of skeletal muscle mass. Depending on the muscular dystrophy, the muscle weakness varies in degree of severity. The majority of myopathies are due to genetic events leading to a loss of function of key genes involved in muscle function. Although there is until now no curative treatment to stop the progression of most myopathies, a significant number of experimental gene- and cell-based strategies and approaches have been and are being tested in vitro and in animal models, aiming to restore gene function. Genome editing using programmable endonucleases is a powerful tool for modifying target genome sequences and has been extensively used over the last decade to correct in vitro genetic defects of many single-gene diseases. By inducing double-strand breaks (DSBs), the engineered endonucleases specifically target chosen sequences. These DSBs are spontaneously repaired either by homologous recombination in the presence of a sequence template, or by nonhomologous-end joining error prone repair. In this review, we highlight recent developments and challenges for genome-editing based strategies that hold great promise for muscular dystrophies and regenerative medicine.


Muscular Dystrophies/therapy , Animals , CRISPR-Cas Systems/genetics , Cell- and Tissue-Based Therapy , DNA Breaks, Double-Stranded , DNA Repair , Gene Editing , Genetic Therapy , Humans , Muscular Dystrophies/genetics
7.
J Chem Phys ; 144(21): 214202, 2016 Jun 07.
Article En | MEDLINE | ID: mdl-27276950

Absolute frequencies of unperturbed (12)C(16)O transitions from the near-infrared (3-0) band were measured with uncertainties five-fold lower than previously available data. The frequency axis of spectra was linked to the primary frequency standard. Three different cavity enhanced absorption and dispersion spectroscopic methods and various approaches to data analysis were used to estimate potential systematic instrumental errors. Except for a well established frequency-stabilized cavity ring-down spectroscopy, we applied the cavity mode-width spectroscopy and the one-dimensional cavity mode-dispersion spectroscopy for measurement of absorption and dispersion spectra, respectively. We demonstrated the highest quality of the dispersion line shape measured in optical spectroscopy so far. We obtained line positions of the Doppler-broadened R24 and R28 transitions with relative uncertainties at the level of 10(-10). The pressure shifting coefficients were measured and the influence of the line asymmetry on unperturbed line positions was analyzed. Our dispersion spectra are the first demonstration of molecular spectroscopy with both axes of the spectra directly linked to the primary frequency standard, which is particularly desirable for the future reference-grade measurements of molecular spectra.

8.
Cell Death Dis ; 6: e1582, 2015 Jan 08.
Article En | MEDLINE | ID: mdl-25569099

Autophagy is a catabolic mechanism facilitating degradation of cytoplasmic proteins and organelles in a lysosome-dependent manner. Autophagy flux is necessary for normal neuronal homeostasis and its dysfunction contributes to neuronal cell death in several neurodegenerative diseases. Elevated autophagy has been reported after spinal cord injury (SCI); however, its mechanism, cell type specificity and relationship to cell death are unknown. Using a rat model of contusive SCI, we observed accumulation of LC3-II-positive autophagosomes starting at posttrauma day 1. This was accompanied by a pronounced accumulation of autophagy substrate protein p62, indicating that early elevation of autophagy markers reflected disrupted autophagosome degradation. Levels of lysosomal protease cathepsin D and numbers of cathepsin-D-positive lysosomes were also decreased at this time, suggesting that lysosomal damage may contribute to the observed defect in autophagy flux. Normalization of p62 levels started by day 7 after SCI, and was associated with increased cathepsin D levels. At day 1 after SCI, accumulation of autophagosomes was pronounced in ventral horn motor neurons and dorsal column oligodendrocytes and microglia. In motor neurons, disruption of autophagy strongly correlated with evidence of endoplasmic reticulum (ER) stress. As autophagy is thought to protect against ER stress, its disruption after SCI could contribute to ER-stress-induced neuronal apoptosis. Consistently, motor neurons showing disrupted autophagy co-expressed ER-stress-associated initiator caspase 12 and cleaved executioner caspase 3. Together, these findings indicate that SCI causes lysosomal dysfunction that contributes to autophagy disruption and associated ER-stress-induced neuronal apoptosis.


Autophagy , Endoplasmic Reticulum Stress , Neurons/pathology , Spinal Cord Injuries/pathology , Animals , Apoptosis , Gray Matter/pathology , Lysosomes/metabolism , Male , Microglia/metabolism , Oligodendroglia/metabolism , Phagosomes/metabolism , Rats, Sprague-Dawley , White Matter/pathology
10.
Plasmonics ; 8(1): 41-43, 2013 Mar.
Article En | MEDLINE | ID: mdl-23504341

It is known that the light scattering from the metal particles deposited on the surfaces of cells can be used for increasing light trapping in the solar cells. In this work, plasmonic structures are composite materials that consisted of silver nanoparticles embedded in dielectric films of TiO x -used as cell antireflection coating. The films are deposited by sol-gel method using spin-on technique. Microstructure of prepared samples is analyzed by SEM observation. Good homogenity and particles density was obtained by this simple, cheap, and short time-demanding method. We demonstrate that due to light scattering by metal particles, the plasmonic-ARC layer is more effective than TiO x layer without Ag nanoparticles. Implementation of nanoparticles on bare cell surface was carried out too. The influence of the plasmonic structures on the silicon solar cells parameters is presented as well. We announce about 5 % additional growth in short circuit current for cells with nanoparticles.

11.
Anim Genet ; 44(3): 311-24, 2013 Jun.
Article En | MEDLINE | ID: mdl-23171373

Both cat breeders and the lay public have interests in the origins of their pets, not only in the genetic identity of the purebred individuals, but also in the historical origins of common household cats. The cat fancy is a relatively new institution with over 85% of its 40-50 breeds arising only in the past 75 years, primarily through selection on single-gene aesthetic traits. The short, yet intense cat breed history poses a significant challenge to the development of a genetic marker-based breed identification strategy. Using different breed assignment strategies and methods, 477 cats representing 29 fancy breeds were analysed with 38 short tandem repeats, 148 intergenic and five phenotypic single nucleotide polymorphisms. Results suggest the frequentist method of Paetkau (single nucleotide polymorphisms = 0.78, short tandem repeats = 0.88) surpasses the Bayesian method of Rannala and Mountain (single nucleotide polymorphisms = 0.56, short tandem repeats = 0.83) for accurate assignment of individuals to the correct breed. Additionally, a post-assignment verification step with the five phenotypic single nucleotide polymorphisms accurately identified between 0.31 and 0.58 of the misassigned individuals raising the sensitivity of assignment with the frequentist method to 0.89 and 0.92 for single nucleotide polymorphisms and short tandem repeats respectively. This study provides a novel multistep assignment strategy and suggests that, despite their short breed history and breed family groupings, a majority of cats can be assigned to their proper breed or population of origin, that is, race.


Breeding , Cats/genetics , Genetic Variation , Genotyping Techniques/methods , Animals , Bayes Theorem , Gene Frequency , Genetic Markers , Genotype , Microsatellite Repeats , Phenotype , Polymorphism, Single Nucleotide , Species Specificity
12.
Nucleic Acids Res ; 39(21): 9085-92, 2011 Nov.
Article En | MEDLINE | ID: mdl-21880598

In the eukaryotic nucleus, genes are transcribed in transcription factories. In the present review, we re-evaluate the models of transcription factories in the light of recent and older data. Based on this analysis, we propose that transcription factories result from the aggregation of RNA polymerase II-containing pre-initiation complexes assembled next to each other in the nuclear space. Such an aggregation can be triggered by the phosphorylation of the C-terminal domain of RNA polymerase II molecules and their interaction with various transcription factors. Individual transcription factories would thus incorporate tissue-specific, co-regulated as well as housekeeping genes based only on their initial proximity to each other in the nuclear space. Targeting genes to be transcribed to protein-dense factories that contain all factors necessary for transcription initiation and elongation through chromatin templates clearly favors a more economical utilization and better recycling of the transcription machinery.


Cell Nucleus/genetics , Genome , Transcription, Genetic , Models, Genetic , Transcriptional Activation
13.
Mol Cell Biochem ; 351(1-2): 143-8, 2011 May.
Article En | MEDLINE | ID: mdl-21312056

Our previous studies identified 4-pyridone-3-carboxamide-1-ß-D-ribonucleoside (4PYR) phosphates in human erythrocytes. We demonstrated formation of these nucleotides by phosphorylation of 4PYR and potential toxicity due to disruption of erythrocyte energy balance. This study aimed to evaluate the ability of the other cell types to phosphorylate 4PYR to characterize function and toxicity of these compounds. Homogenates of rat heart, kidneys, and liver were used to study the rate of 4PYR phosphorylation in the presence of ATP. In another experiment, 4PYR was administered into mouse as repeated subcutaneous injections and into rats as intraperitoneal infusion. After 7 days, heart, liver, kidney, lungs, and skeletal muscle were collected, and the concentration of 4PYR nucleotides was evaluated. HPLC was used to measure 4PYR and 4PYR nucleotides in homogenate and specimens from in vivo experiments. 4PYR was rapidly phosphorylated by the liver homogenate (390 ± 27 nmol/min/g wet wt). Significant rates were reported in the heart and kidneys' homogenates: 34.3 ± 4.3 nmol/min/g and 33.2 ± 9.2 nmol/min/g, respectively. Phosphorylation of 4PYR was almost completely inhibited by adenosine kinase inhibitor 5'-iodotubercidin. Administration of 4PYR in vivo resulted in accumulation of 4PYR monophosphate in the liver, heart, skeletal muscle, and lung (20-220 nmol/g dry wt) except kidney (<1 nmol/g). In contrast to erythrocytes, no 4PYR triphosphate formation (<1 nmol/g) was observed in any of the organs studied. We conclude that not only the erythrocytes but also other cell types are capable of phosphorylating 4PYR to form 4PYR monophosphate. Potential toxicity or physiological role of 4PYR in peripheral organs could be considered, but mechanisms will be different from that in erythrocytes.


Nucleosides/metabolism , Pyridones/metabolism , Animals , Chromatography, High Pressure Liquid , Male , Mice , Mice, Inbred DBA , Nucleosides/administration & dosage , Phosphorylation , Pyridones/administration & dosage , Rats , Rats, Wistar
14.
Forensic Sci Int Genet ; 5(1): 33-42, 2011 Jan.
Article En | MEDLINE | ID: mdl-20457082

The domestic cat is the one of the most popular pets throughout the world. A by-product of owning, interacting with, or being in a household with a cat is the transfer of shed fur to clothing or personal objects. As trace evidence, transferred cat fur is a relatively untapped resource for forensic scientists. Both phenotypic and genotypic characteristics can be obtained from cat fur, but databases for neither aspect exist. Because cats incessantly groom, cat fur may have nucleated cells, not only in the hair bulb, but also as epithelial cells on the hair shaft deposited during the grooming process, thereby generally providing material for DNA profiling. To effectively exploit cat hair as a resource, representative databases must be established. The current study evaluates 402 bp of the mtDNA control region (CR) from 1394 cats, including cats from 25 distinct worldwide populations and 26 breeds. Eighty-three percent of the cats are represented by 12 major mitotypes. An additional 8.0% are clearly derived from the major mitotypes. Unique sequences are found in 7.5% of the cats. The overall genetic diversity for this data set is 0.8813±0.0046 with a random match probability of 11.8%. This region of the cat mtDNA has discriminatory power suitable for forensic application worldwide.


Cats/genetics , DNA, Mitochondrial/genetics , Databases, Nucleic Acid , Forensic Medicine/methods , Animals , Base Sequence , DNA Fingerprinting/methods , Genetic Variation , Genotype , Hair/chemistry , Locus Control Region/genetics , Mitochondria/genetics , Repetitive Sequences, Nucleic Acid , Sequence Analysis, DNA
15.
Minerva Cardioangiol ; 58(1): 1-10, 2010 Feb.
Article En | MEDLINE | ID: mdl-20145590

AIM: The aim of this study was to assess cardiac mortality in patients with reduced ejection fraction (EF< or =45%) and anemia (Hb< or =12 g/dL) undergoing coronary stenting and to investigate whether iron-deficiency anemia influenced outcome when compared to non-anemic patients or patients with other types of anemia. METHODS: One hundred twenty consecutive patients undergoing percutaneous coronary intervention (PCI) between April 2003 and December 2005 were identified and followed for a median of 30 months. Patients were divided into 2 groups, anemic (Hb< or =12 g/dL) and non-anemic. Anemic patients were then divided into 3 sub-groups based on laboratory analysis and anemia work-up: iron-deficiency, malignancy-associated, and anemia of chronic disease (including chronic kidney disease). Mortality rates and cause of death were retrieved using both the Social Security database and the hospital records. RESULTS: Thirty-one percent of patients had iron deficiency, 24% had a malignancy-associated anemia and 45% had anemia of chronic disease. Overall mortality was 12% of which 29% was cardiac death. All-cause and cardiac mortality were significantly higher in anemic vs. non-anemic patients, (31% vs. 6%, P<0.001, and 10% vs. 1%, P=0.016, respectively). Iron-deficiency anemia strongly predicted cardiac mortality (33% vs. 1% in non-anemic patients, P<0.001), while malignancy-associated anemia was the strongest predictor of non-cardiac death (57% vs. 4% in non-anemic patients, P<0.001). Anemia of chronic disease neither predicted cardiac nor non-cardiac death. CONCLUSIONS: To the authors' knowledge, this is the first study to show that iron-deficiency anemia is a strong predictor of cardiac death when compared to patients with other types of anemia or to non-anemic patients.


Anemia, Iron-Deficiency/complications , Angioplasty, Balloon, Coronary , Heart Diseases/complications , Heart Diseases/mortality , Stents , Ventricular Dysfunction, Left/complications , Aged , Female , Humans , Male , Middle Aged , Prognosis , Retrospective Studies
16.
Nucleosides Nucleotides Nucleic Acids ; 27(6): 867-71, 2008 Jun.
Article En | MEDLINE | ID: mdl-18600554

Because mutation of AMP deaminase 1 gene leading to reduced AMP deaminase activity may result in protection of cardiac function in patients with heart disease, inhibitors of AMP deaminase (AMPD) may have therapeutic applications. This study evaluated the effect of a specific inhibitor of AMP deaminase 3-[2-(3-carboxy-4-bromo-5,6,7,8-tetrahydronaphthyl)ethyl]-3,6,7,8-tetrahydroimidazo [4,5-d][1,3]diazepin-8-ol (AMPDI) on the isolated human enzyme and on nucleotide catabolism in rat cardiomyocytes. AMPDI effectively inhibited isolated human AMPD with an IC(50) = 0.5 micro M. AMPDI was much less effective with isolated cardiomyocytes (IC(50) = 0.5 mM). AMPDI is a very effective inhibitor of AMPD that despite lower efficiency in the cell system examined could be useful for in vivo studies.


AMP Deaminase/antagonists & inhibitors , Azepines/pharmacology , Enzyme Inhibitors/pharmacology , Imidazoles/pharmacology , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/enzymology , Adenosine/metabolism , Animals , Azepines/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Humans , Imidazoles/chemical synthesis , Inosine Monophosphate/metabolism , Myocytes, Cardiac/metabolism , Rats
17.
Nucleosides Nucleotides Nucleic Acids ; 27(6): 876-80, 2008 Jun.
Article En | MEDLINE | ID: mdl-18600556

Changes in AMP deaminase (AMPD) activity influence heart function and progression of heart disease, but the underlying mechanism is unknown. We evaluated the effect of purine riboside (Purr) on the activity of AMPD in perfused rat hearts and in isolated rat cardiomyocytes. Brief perfusion of the pre-ischemic heart with 200 micro M Purr resulted in activation of AMPD, more pronounced degradation of the adenine nucleotides, and reduced recovery of the adenine nucleotide pool during reperfusion. Brief incubation of rat cardiomyocytes with 200 micro M Purr also activated AMPD, while prolonged exposure resulted in enzyme inhibition. We conclude that Purr activates AMPD, whereas metabolites of this compound may inhibit the enzyme.


AMP Deaminase/metabolism , Heart/drug effects , Ischemia/metabolism , Myocardium/enzymology , Purine Nucleosides/pharmacology , Reperfusion , Ribonucleosides/pharmacology , AMP Deaminase/antagonists & inhibitors , Animals , Enzyme Activation/drug effects , Myocardium/pathology , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Nucleotides/metabolism , Rats
18.
Biochimie ; 90(11-12): 1656-66, 2008.
Article En | MEDLINE | ID: mdl-18627787

Neuroblastoma (NB), the most common extracranial solid tumors in children, presents with numerous genetic abnormalities that accumulate in a very short lifetime. To better understand this process, we have induced DNA double-strand breaks in NB cell lines and analyzed the activation of the ATM-H2AX/Chk2-p53 signaling pathway. We have found that NB cells could be classified into two distinct groups. The first group strongly expressed activated Chk2, displayed an important sub-G1 population, expressed very low levels of p21, and exhibited an attenuated G1 arrest. Conversely, the second group weakly expressed Chk2 pT68, displayed no sub-G1 cell population, strongly expressed p21, and exhibited a functional G1 arrest. These findings were independent of the MYCN amplification or p53 status of the NB cell lines tested. Interestingly, most p21 weakly expressing NB cells expressed neuron-specific enolase and Bcl2, two markers of N-type NB cells, but did not express vimentin, a marker of S-type NB cells. The expression profile was reversed in the p21 strongly expressing NB cells which highly expressed vimentin. Along with additional data, our findings lead us to propose that N-type-like NB cells would survive under stress conditions by antagonizing the Chk2-dependent apoptosis pathway, whereas S-type-like NB cells would survive by down-regulating Chk2 expression to facilitate the crossing of the senescence barrier.


DNA Breaks, Double-Stranded , Neuroblastoma/metabolism , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Vimentin/metabolism , rho GTP-Binding Proteins/metabolism , Cell Line, Tumor , Checkpoint Kinase 2 , Humans , Transfection
19.
Anim Genet ; 38(4): 371-7, 2007 Aug.
Article En | MEDLINE | ID: mdl-17655554

Seventeen commercial and research laboratories participated in two comparison tests under the auspices of the International Society for Animal Genetics to develop an internationally tested, microsatellite-based parentage and identification panel for the domestic cat (Felis catus). Genetic marker selection was based on the polymorphism information content and allele ranges from seven random-bred populations (n = 261) from the USA, Europe and Brazil and eight breeds (n = 200) from the USA. Nineteen microsatellite markers were included in the comparison test and genotyped across the samples. Based on robustness and efficiency, nine autosomal microsatellite markers were ultimately selected as a single multiplex 'core' panel for cat identification and parentage testing. Most markers contained dinucleotide repeats. In addition to the autosomal markers, the panel included two gender-specific markers, amelogenin and zinc-finger XY, which produced genotypes for both the X and Y chromosomes. This international cat parentage and identification panel has a power of exclusion comparable to panels used in other species, ranging from 90.08% to 99.79% across breeds and 99.47% to 99.87% in random-bred cat populations.


Cats/classification , Microsatellite Repeats , Alleles , Animals , Cats/genetics , Genetic Markers , Genotype , Polymorphism, Genetic
20.
Antimicrob Agents Chemother ; 51(7): 2523-30, 2007 Jul.
Article En | MEDLINE | ID: mdl-17404006

Novel N(4)-hydroxy- and 5-methyl-modified beta-L-deoxycytidine analogues were synthesized and evaluated as anti-hepatitis B virus (HBV) agents. Their in vitro efficiencies were investigated in HepG2.2.15 cells stably transfected with HBV. beta-L-2',3'-Didehydro-2',3'-dideoxy-N(4)-hydroxycytidine (beta-L-Hyd4C) was most effective in reducing secreted HBV DNA (50% effective concentration [EC(50)], 0.03 microM), followed by beta-L-2',3'-dideoxy-3'-thia-N(4)-hydroxycytidine (EC(50), 0.51 microM), beta-L-2',3'-dideoxy-N(4)-hydroxycytidine (EC(50), 0.55 microM), and beta-L-5-methyl-2'-deoxycytidine (EC(50), 0.9 microM). The inhibition of the presumed target, the HBV DNA polymerase, by the triphosphates of some of the beta-L-cytidine derivatives was also assessed. In accordance with the cell culture data, beta-L-Hyd4C triphosphate was the most active inhibitor, with a 50% inhibitory concentration of 0.21 microM. The cytotoxicities of some of the 4-NHOH-modified beta-L-nucleosides were dramatically lower than those of the corresponding cytidine analogues with the unmodified 4-NH(2) group. The 50% cytotoxic concentrations for beta-L-Hyd4C in HepG2 and HL-60 cells were 2,500 microM and 3,500 microM, respectively. In summary, our results demonstrate that at least beta-L-Hyd4C can be recommended as a highly efficient and extremely selective inhibitor of HBV replication for further investigations.


Antiviral Agents/pharmacology , Deoxycytidine/analogs & derivatives , Deoxycytidine/pharmacology , Hepatitis B virus/drug effects , Virus Replication/drug effects , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Antiviral Agents/toxicity , Carcinoma, Hepatocellular/metabolism , Cell Line, Tumor , Deoxycytidine/metabolism , Deoxycytidine/toxicity , Dose-Response Relationship, Drug , HL-60 Cells , Hepatitis B virus/physiology , Humans , Inhibitory Concentration 50 , Liver Neoplasms/metabolism , Molecular Structure , Nucleic Acid Synthesis Inhibitors , Time Factors , Transfection
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