Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 31
Filter
1.
Braz J Med Biol Res ; 54(8): e10850, 2021.
Article in English | MEDLINE | ID: mdl-34037096

ABSTRACT

The conversion of adenosine to inosine is catalyzed by adenosine deaminase (ADA) (EC 3.5.4.4), which has two isoforms in humans (ADA1 and ADA2) and belongs to the zinc-dependent hydrolase family. ADA modulates lymphocyte function and differentiation, and regulates inflammatory and immune responses. This study investigated ADA activity in lymphocyte-rich peripheral blood mononuclear cells (PBMCs) in the absence of disease. The viability of lymphocyte-rich PBMCs isolated from humans and kept in 0.9% saline solution at 4-8°C was analyzed over 20 h. The incubation time and biochemical properties of the enzyme, such as its Michaelis-Menten constant (Km) and maximum velocity (Vmax), were characterized through the liberation of ammonia from the adenosine substrate. Additionally, the presence of ADA protein on the lymphocyte surface was determined by flow cytometry using an anti-CD26 monoclonal human antibody, and the PBMCs showed long-term viability after 20 h. The ADA enzymatic activity was linear from 15 to 120 min of incubation, from 2.5 to 12.5 µg of protein, and pH 6.0 to 7.4. The Km and Vmax values were 0.103±0.051 mM and 0.025±0.001 nmol NH3·mg-1·s-1, respectively. Zinc and erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA) inhibited enzymatic activity, and substrate preference was given to adenosine over 2'-deoxyadenosine and guanosine. The present study provides the biochemical characterization of ADA in human lymphocyte-rich PBMCs, and indicates the appropriate conditions for enzyme activity quantification.


Subject(s)
Adenosine Deaminase , Dipeptidyl Peptidase 4 , Adenine , Humans , Leukocytes, Mononuclear , Lymphocytes
2.
Braz. j. med. biol. res ; 54(8): e10850, 2021. tab, graf
Article in English | LILACS | ID: biblio-1249328

ABSTRACT

The conversion of adenosine to inosine is catalyzed by adenosine deaminase (ADA) (EC 3.5.4.4), which has two isoforms in humans (ADA1 and ADA2) and belongs to the zinc-dependent hydrolase family. ADA modulates lymphocyte function and differentiation, and regulates inflammatory and immune responses. This study investigated ADA activity in lymphocyte-rich peripheral blood mononuclear cells (PBMCs) in the absence of disease. The viability of lymphocyte-rich PBMCs isolated from humans and kept in 0.9% saline solution at 4-8°C was analyzed over 20 h. The incubation time and biochemical properties of the enzyme, such as its Michaelis-Menten constant (Km) and maximum velocity (Vmax), were characterized through the liberation of ammonia from the adenosine substrate. Additionally, the presence of ADA protein on the lymphocyte surface was determined by flow cytometry using an anti-CD26 monoclonal human antibody, and the PBMCs showed long-term viability after 20 h. The ADA enzymatic activity was linear from 15 to 120 min of incubation, from 2.5 to 12.5 µg of protein, and pH 6.0 to 7.4. The Km and Vmax values were 0.103±0.051 mM and 0.025±0.001 nmol NH3·mg-1·s-1, respectively. Zinc and erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA) inhibited enzymatic activity, and substrate preference was given to adenosine over 2′-deoxyadenosine and guanosine. The present study provides the biochemical characterization of ADA in human lymphocyte-rich PBMCs, and indicates the appropriate conditions for enzyme activity quantification.


Subject(s)
Humans , Adenosine Deaminase , Dipeptidyl Peptidase 4 , Leukocytes, Mononuclear , Adenine , Lymphocytes
3.
J Immunol Methods ; 475: 112618, 2019 12.
Article in English | MEDLINE | ID: mdl-31181212

ABSTRACT

Fluorochrome selection is a key step in designing multi-color antibody panels. The list of available fluorochromes is continuously growing, fitting current needs in clinical flow cytometry to simultaneously use more markers to better define multiple leukocyte subpopulations in a single tube. Several criteria guide fluorochrome selection: i) the fluorescence profiles (excitation and emission), ii) relative brightness, iii) fluorescence overlap, iv) fluorochrome stability, and v) reproducible conjugation to antibodies. Here we used 75 samples (45 bone marrow and 30 blood) to illustrate EuroFlow strategies for evaluation of compatible fluorochromes, and how the results obtained guide fluorochrome selection as a critical step in the antibody-panel building process. Our results allowed identification of optimal fluorescence profiles (e.g. higher fluorescence intensity and/or resolution with limited fluorescence overlap into neighbor channels) for brilliant violet (BV)421 and BV510 in the violet laser and allophycocyanin (APC) hilite 7 (H7) or APC C750 in the red laser vs. other candidate fluorochromes generally applied for the same detectors and here evaluated. Moreover, evaluation of the same characteristics for another group of fluorochromes (e.g. BV605, BV650, PE CF594, AF700 or APC AF700) guided selection of the most appropriate fluorochrome conjugates to be combined in a multi-color antibody panel. Albeit this is a demanding approach, it could be successfully applied for selection of fluorochrome combinations for the EuroFlow antibody panels for diagnosis, classification and monitoring of hematological malignancies and primary immunodeficiencies. Consequently, sets of 8-, 10- and 12-color fluorochrome combinations are proposed as frame of reference for initial antibody panel design.


Subject(s)
Flow Cytometry/methods , Fluorescent Dyes , Immunophenotyping/methods , Humans
4.
J Invertebr Pathol ; 162: 26-42, 2019 03.
Article in English | MEDLINE | ID: mdl-30735763

ABSTRACT

The red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) is threatening the palm family worldwide, causing important economic losses. Current tactics to manage the weevil are largely based on chemical control, although the use of pesticides is hampered by several environmental constraints. Since the first introduction of RPW in Spain in 1996 and during its progressive spread around the Mediterranean basin, the number of reports of natural infection of RPW populations by entomopathogenic fungi (EPF) has been rising for 15 years, and this rise could support a pest-mediated EPF spread. To challenge this hypothesis, we assessed the usefulness of the region of elongation factor 1-alpha (EF1-α), Bloc nuclear intergenic region (Bloc) and inter simple sequence repeat (ISSR) markers, alone or in combination, to infer the relationships among Mediterranean Beauveria and Metarhizium strains isolated from the RPW. Second, the effect of abiotic factors, such as temperature, humidity and UV-B radiation, on the germination and growth of these EPFs strains as a function of their genealogy and geographic origin were determined. Finally, the pathogenicity of strains from different genetic clades was evaluated against larvae and adults of R. ferrugineus. The phylogenetic analysis based on the EF-1α gene identified eight different sequences among 24 fungal isolates of four fungal species. Similar clades were clustered when Bloc and ISSR analyses were performed. The results showed that strains of different origins were clustered in the same clade, and this outcome could be explained by an RPW-mediated EPF spread that was also influenced by time, geographical and other RPW related factors. Neither the response to abiotic factors nor virulence to RPW larvae and adults were related to the sequence type, with all B. bassiana strains well adapted to Mediterraneam climatic conditions. Taken together, these findings may help to select the best strain for RPW management.


Subject(s)
Beauveria , Moths/microbiology , Mycoses/diagnosis , Pest Control, Biological/methods , Weevils/microbiology , Animals , Arecaceae , Beauveria/genetics , Beauveria/pathogenicity , Genetic Markers , Hypocreales/genetics , Hypocreales/pathogenicity , Incidence , Introduced Species , Metarhizium/genetics , Metarhizium/pathogenicity , Mycoses/transmission , Pathology, Molecular , Phylogeny , Spain , Virulence
5.
Leukemia ; 30(10): 2064-2073, 2016 10.
Article in English | MEDLINE | ID: mdl-27125308

ABSTRACT

Although NOD-SCID IL2Rγ-/- (NSG) xenograft mice are currently the most frequently used model to study human leukemia in vivo, the absence of a human niche severely hampers faithful recapitulation of the disease. We used NSG mice in which ceramic scaffolds seeded with human mesenchymal stromal cells were implanted to generate a human bone marrow (huBM-sc)-like niche. We observed that, in contrast to the murine bone marrow (mBM) niche, the expression of BCR-ABL or MLL-AF9 was sufficient to induce both primary acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL). Stemness was preserved within the human niches as demonstrated by serial transplantation assays. Efficient engraftment of AML MLL-AF9 and blast-crisis chronic myeloid leukemia patient cells was also observed, whereby the immature blast-like phenotype was maintained in the huBM-sc niche but to a much lesser extent in mBM niches. We compared transcriptomes of leukemias derived from mBM niches versus leukemias from huBM-like scaffold-based niches, which revealed striking differences in the expression of genes associated with hypoxia, mitochondria and metabolism. Finally, we utilized the huBM-sc MLL-AF9 B-ALL model to evaluate the efficacy of the I-BET151 inhibitor in vivo. In conclusion, we have established human niche models in which the myeloid and lymphoid features of BCR-ABL+ and MLL-AF9+ leukemias can be studied in detail.


Subject(s)
Bone Marrow/pathology , Disease Models, Animal , Fusion Proteins, bcr-abl , Leukemia, Myeloid, Acute/pathology , Myeloid-Lymphoid Leukemia Protein , Oncogene Proteins, Fusion , Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology , Animals , Humans , Mice , Transplantation, Heterologous
6.
Exp Appl Acarol ; 68(1): 1-20, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26471983

ABSTRACT

Dispersal can be an essential factor affecting the biological control of pests. Tetranychus urticae Koch (Acari: Tetranychidae) is a cosmopolitan and polyphagous species that may reach the pest status in many cropping systems including clementine orchards, where it may be found both in the trees and the associated flora. In a previous study, we demonstrated that the use of a ground cover of Festuca arundinacea Schreber (Poaceae) offered a better regulation of T. urticae populations than traditional alternatives (bare soil, multifloral wild cover). Therefore, we decided to study the ambulatory dispersal of mites crawling up and down tree trunks in a clementine mandarin orchard grown in association with a F. arundinacea cover for one season. The highest ambulatory migration rate was upward from the cover to the canopy. Multivariate regressions showed that the dynamics of T. urticae populations in the trees was strongly related to that of Phytoseiidae mites, their main natural predators. Surprisingly, canopy populations were not related to those on the ground cover or to those dispersing from it. When T. urticae individuals collected from the ground cover, the tree trunk, and the canopy were subjected to molecular analyses, the optimal number of genetic clusters (demes) was two. One clustergrouped individuals dispersed from the ground cover (e.g. collected on tree trunks) and 27.5% of individuals collected in the ground cover. The second cluster grouped all the individuals collected from trees and 72.5% of those collected in the cover. Interestingly, none of the individuals collected from the tree canopies was grouped with the first deme. This result may be taken as indicative that grass-adapted T. urticae individuals are unable to satisfactorily colonize and establish on the trees and provides evidence that host adaptation can hamper dispersal and establishment of the ground cover deme on trees, contributing to a better natural regulation of this pest species in citrus.


Subject(s)
Animal Distribution , Citrus/parasitology , Festuca/growth & development , Food Chain , Tetranychidae/physiology , Agriculture , Animals , Citrus/growth & development , Pest Control, Biological
7.
Leukemia ; 29(3): 625-35, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25184385

ABSTRACT

As the transcriptional coactivator CITED2 (CBP/p300-interacting-transactivator-with-an ED-rich-tail 2) can be overexpressed in acute myeloid leukemia (AML) cells, we analyzed the consequences of high CITED2 expression in normal and AML cells. CITED2 overexpression in normal CD34(+) cells resulted in enhanced hematopoietic stem and progenitor cell (HSPC) output in vitro, as well as in better hematopoietic stem cell (HSC) engraftability in NSG (NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ) mice. This was because of an enhanced quiescence and maintenance of CD34(+)CD38(-) HSCs, due in part to an increased expression of the cyclin-dependent kinase inhibitor CDKN1A. We demonstrated that PU.1 is a critical regulator of CITED2, as PU.1 repressed CITED2 expression in a DNA methyltransferase 3A/B (DNMT3A/B)-dependent manner in normal CD34(+) cells. CD34(+) cells from a subset of AML patients displayed higher expression levels of CITED2 as compared with normal CD34(+) HSPCs, and knockdown of CITED2 in AML CD34(+) cells led to a loss of long-term expansion, both in vitro and in vivo. The higher CITED2 expression resulted from reduced PU.1 activity and/or dysfunction of mutated DNMT3A/B. Collectively, our data demonstrate that increased CITED2 expression results in better HSC maintenance. In concert with low PU.1 levels, this could result in a perturbed myeloid differentiation program that contributes to leukemia maintenance.


Subject(s)
Gene Expression Regulation, Leukemic , Hematopoietic Stem Cells/metabolism , Leukemia, Myeloid, Acute/genetics , Proto-Oncogene Proteins/genetics , Repressor Proteins/genetics , Trans-Activators/genetics , Animals , Antigens, CD34/genetics , Antigens, CD34/metabolism , Cell Proliferation , Cyclin-Dependent Kinase Inhibitor p21/genetics , Cyclin-Dependent Kinase Inhibitor p21/metabolism , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA (Cytosine-5-)-Methyltransferases/metabolism , DNA Methyltransferase 3A , Female , Graft Survival , Hematopoietic Stem Cell Transplantation , Hematopoietic Stem Cells/pathology , Humans , Leukemia, Myeloid, Acute/metabolism , Leukemia, Myeloid, Acute/pathology , Mice , Mice, Inbred NOD , Mutation , Proto-Oncogene Proteins/metabolism , Repressor Proteins/metabolism , Signal Transduction , Trans-Activators/metabolism , Transplantation, Heterologous , DNA Methyltransferase 3B
8.
Opt Express ; 22(11): 13600-15, 2014 Jun 02.
Article in English | MEDLINE | ID: mdl-24921554

ABSTRACT

We demonstrate logic functionalities in a high-speed all-optical logic circuit based on differential Mach-Zehnder interferometers with semiconductor optical amplifiers as the nonlinear optical elements. The circuit, implemented by hybrid integration of the semiconductor optical amplifiers on a planar lightwave circuit platform fabricated in silica glass, can be flexibly configured to realize a variety of Boolean logic gates. We present both simulations and experimental demonstrations of cascaded all-optical operations for 80-Gb/s on-off keyed data.

9.
Gen Comp Endocrinol ; 194: 248-56, 2013 Dec 01.
Article in English | MEDLINE | ID: mdl-24095808

ABSTRACT

The role of thyrotropin (thyroid-stimulating hormone, TSH) in driving peripheral thyroid function in non-mammalian species is still poorly understood. Thyroxine (T4), the principal hormone released from the thyroid gland in response to TSH stimulation, circulates with a robust daily rhythm in the teleost fish the red drum. Previous research suggests that the red drum T4 cycle is circadian in nature, driven by TSH secretion in the early photophase and inhibited by T4 feedback in the early scotophase. To determine whether TSH is produced in a pattern consistent with feedback inhibition by this T4 cycle, we used quantitative real time PCR (qPCR) to quantify the daily cycle of expression of the pituitary TSH subunits GSUα, and TSHß. We found that TSH expression cycled inversely to, and 6-12 h out of phase with, the T4 cycle, consistent with the hypothesis that TSH secretion drives the T4 cycle. To examine the potential role of deiodinases in negative feedback regulation of this TSH cycle, we also utilized qPCR to assess the pituitary expression patterns of the TH activating enzyme outer-ring deiodinase (Dio2) and the TH deactivating enzyme inner-ring deiodinase (Dio3). Dio2 was not expressed with an obvious daily cycle, whereas Dio3 expression mirrored the expression of TSH. These results are consistent with circulating T4 providing the negative feedback signal controlling both TSH production and Dio3 expression in the pituitary, and suggest that TH inactivation by inner ring deiodination is an important component of TSH negative feedback control.


Subject(s)
Iodide Peroxidase/genetics , RNA, Messenger/genetics , Thyrotropin/genetics , Animals , Perciformes/metabolism , Phylogeny , Pituitary Gland/metabolism , Thyroxine/genetics , Iodothyronine Deiodinase Type II
10.
Eur J Gastroenterol Hepatol ; 25(9): 1024-32, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23708277

ABSTRACT

INTRODUCTION: Radiofrequency ablation (RFA) is a valuable treatment option in Barrett's esophagus resulting in eradication of dysplasia and conversion of all Barrett's epithelium into normal squamous epithelium. In Barrett's esophagus, esophageal impedance monitoring is hampered by low baseline impedance values. Whether these low baselines are caused by an intrinsically low impedance of cylindrical epithelium or by the excessive reflux itself is hitherto unknown. Data on esophageal motility after RFA are scarce. Our aim was to examine the effect of RFA on esophageal motility and esophageal baseline impedance in patients with Barrett's esophagus. METHODS: In 10 patients, conventional esophageal manometry and 24-h pH-impedance measurements were performed before and after RFA. The number and type of reflux episodes were assessed and baseline impedance values were measured in all recording segments. In another five patients, high-resolution manometry was performed before and after RFA. RESULTS: Complete regression of all Barrett's epithelium was achieved in all 15 patients after 3 ± 1 RFA sessions. Overall, no significant motility changes were found after RFA. Patients had excessive acid exposure times before and after RFA [25 (17-42) and 16 (9-24)%, respectively]. Baseline esophageal impedance values were low, with the lowest values in the distal recording segments. RFA increased baseline impedance in all recording segments in the upright position; in the supine position, the effect just failed to reach statistically significant levels. CONCLUSION: RFA did not alter esophageal motility significantly. Low esophageal baseline impedance levels in patients with Barrett's esophagus reflect, at least in part, intrinsic impedance properties of cylindrical epithelium, as baselines increased after conversion into neosquamous epithelium.


Subject(s)
Barrett Esophagus/surgery , Catheter Ablation , Esophagus/surgery , Gastroesophageal Reflux/complications , Gastrointestinal Motility , Barrett Esophagus/diagnosis , Barrett Esophagus/etiology , Barrett Esophagus/physiopathology , Electric Impedance , Esophageal pH Monitoring , Esophagoscopy , Esophagus/pathology , Esophagus/physiopathology , Gastroesophageal Reflux/diagnosis , Gastroesophageal Reflux/physiopathology , Humans , Manometry , Mucous Membrane/pathology , Mucous Membrane/surgery , Treatment Outcome
11.
Leukemia ; 27(5): 1116-26, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23178754

ABSTRACT

The MLL-AF9 fusion gene is associated with aggressive leukemias of both the myeloid and lymphoid lineage in infants, whereas in adults, this translocation is mainly associated with acute myeloid leukemia. These observations suggest that differences exist between fetal and adult tissues in terms of the 'cell of origin' from which the leukemia develops. Here we show that depending on extrinsic cues, human neonatal CD34(+) cells are readily immortalized along either the myeloid or lymphoid lineage upon MLL-AF9 expression and give rise to mainly lymphoid leukemia in immunocompromised mice. In contrast, immortalization of adult bone marrow CD34(+) cells is more difficult to achieve and is myeloid-biased, even when MLL-AF9 is expressed in purified hematopoietic stem cells (HSCs). Transcriptome analysis identified enrichment of HSC but not progenitor gene signatures in MLL-AF9-expressing cells. Although not observed in adult cells, neonatal cells expressing MLL-AF9 were enriched for gene signatures associated with poor prognosis, resistance to chemotherapeutic agents and MYC signaling. These results indicate that neonatal cells are inherently more prone to MLL-AF9-mediated immortalization than adult cells and suggest that intrinsic properties of the cell of origin, in addition to extrinsic cues, dictate lineage of the immortalized cell.


Subject(s)
Cell Lineage , Cell Transformation, Neoplastic , Hematopoietic Stem Cells/pathology , Myeloid-Lymphoid Leukemia Protein/physiology , Oncogene Proteins, Fusion/physiology , Animals , Antigens, CD19/analysis , Female , Humans , Infant, Newborn , Leukemia, Myeloid, Acute/etiology , Lewis X Antigen/analysis , Lipopolysaccharide Receptors/analysis , Mice , Mice, SCID , Myeloid-Lymphoid Leukemia Protein/genetics , Oncogene Proteins, Fusion/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/etiology
12.
Int Forum Allergy Rhinol ; 2(6): 487-95, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22777956

ABSTRACT

BACKGROUND: Craniofacial resection (CFR) has been the standard of care for malignant tumors of the anterior skull base (ASB). However, during the past 2 decades, transnasal endoscopic resection (TER) has gained significant popularity. The purpose of this study is to compare CFR and TER with respect to perioperative and oncologic outcomes. METHODS: Retrospective analysis at a tertiary care medical center of 82 consecutive patients undergoing resection of tumors of the ASB between 1997 and 2011. RESULTS: Thirty-four patients underwent TER, while 48 patients underwent CFR. There was no statistical difference in major complications between the two groups (p = 0.29). However, TER patients had shorter operating room times (284 minutes for TER, 620 minutes for CFR; p < 0.001), lower intraoperative blood loss (675 mL for TER, 1000 mL for CFR; p = 0.005), shorter intensive care unit (ICU) stays (0 days for TER, 3 days for CFR; p < 0.001), and shorter hospital stays (4.5 days for TER; 7 days for CFR; p < 0.001). There were no differences for the rates of en bloc resection, negative margins, or disease-specific mortality. Subanalysis yielded a median follow-up of 5 years postoperatively. There were no differences in disease-specific mortality or recurrences in this group. CONCLUSION: Patients undergoing TER for tumors of the ASB are more likely to leave the ICU and the hospital earlier than their CFR counterparts. Furthermore, for carefully selected patients undergoing TER, excellent oncologic outcomes with survival and recurrence rates similar to patients undergoing CFR may be achieved. Comparison of oncologic outcomes, however, may be limited by discrepancy in histologic grade and clinical stage between the two groups. Nonetheless, TER seems to be an excellent alternative to CFR in appropriately selected patients.


Subject(s)
Endoscopy/methods , Skull Base Neoplasms/surgery , Combined Modality Therapy , Disease-Free Survival , Face/surgery , Female , Humans , Length of Stay/statistics & numerical data , Male , Middle Aged , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/surgery , Neoplasm Staging , Operative Time , Paranasal Sinuses/surgery , Postoperative Complications/etiology , Retrospective Studies , Skull/surgery , Skull Base Neoplasms/pathology , Treatment Outcome
13.
Gen Comp Endocrinol ; 177(1): 70-5, 2012 May 15.
Article in English | MEDLINE | ID: mdl-22387984

ABSTRACT

Thyrotropin (TSH) is a pituitary glycoprotein hormone heterodimer that binds to its G-protein coupled receptor (TSH-R) at the thyroid to promote the synthesis and secretion of thyroid hormone. Very little is known about TSH-TSH-R interactions in teleost fish. Mammalian gonadotropins have been reported to have an intrinsic ability to activate teleost fish TSH-Rs, suggesting the TSH-R in teleost fish is more promiscuous than in other vertebrates. In this study we utilized the goldfish T(4)-release response and recombinant human TSH analogs as in vivo tools to evaluate the structural constraints on hormone-receptor interactions. We found that four positively charged lysines substituted for neutral or negatively charged amino acids within positions 11-20 of the glycoprotein hormone subunit α (GSUα) significantly increased biological activity of hTSH in fish, as it does in mammals. We further found that bovine follicle stimulating hormone but not luteinizing hormone, whose GSUα subunits also contain four lysine or arginine amino acid residues in the N-terminal portion of GSUα, was thyrotropic in goldfish, suggesting gonadotropin ß subunit contributes to the heterothyrotropic activity. Though recombinant human FSH did not produce a dose-dependent increase in T(4), thyrotropic activity could be acquired with the addition of positively charged amino acids at the N-terminal portion of its GSUα, confirming the importance of the charge on those amino acids for activation of the goldfish TSH-R. These studies demonstrate that mammalian glycoprotein hormone analogs can be utilized to evaluate the conservation of receptor binding and activation mechanisms between fish and mammals.


Subject(s)
Goldfish/metabolism , Receptors, Thyrotropin/metabolism , Animals , Evolution, Molecular , Goldfish/blood , Gonadotropins/blood , Gonadotropins/metabolism , Humans , Immunoassay , Thyrotropin/pharmacology , Thyroxine/blood
14.
Opt Express ; 20(2): 896-904, 2012 Jan 16.
Article in English | MEDLINE | ID: mdl-22274436

ABSTRACT

We propose a novel energy-efficient coherent-optical OFDM transmission scheme based on hybrid optical-electronic signal processing. We demonstrate transmission of a 0.26-Tb/s OFDM superchannel, consisting of 13 x 20-Gb/s polarization-multiplexed QPSK subcarrier channels, over 400-km standard single-mode fiber (SSMF) with BER less than 6.3x10(-4) using all-optical Fourier transform processing and electronic 7-tap blind digital equalization per subchannel. We further explore long-haul transmission over up to 960 km SSMF and show that the electronic signal processing is capable of compensating chromatic dispersion up to 16,000 ps/nm using only 15 taps per subchannel, even in the presence of strong inter-carrier interference.


Subject(s)
Electronics/instrumentation , Electronics/methods , Fiber Optic Technology/instrumentation , Fiber Optic Technology/methods , Fourier Analysis , Equipment Design , Models, Theoretical
15.
Ann Trop Med Parasitol ; 105(5): 385-91, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21929880

ABSTRACT

This study aimed to evaluate the activity of cholinesterases and adenosine deaminase (ADA) in blood and serum of rats infected with Trypanosoma cruzi. Twelve adult rats were used in the experiment divided into two uniform groups. Rodents from group A (control group) were non-infected and animals from group B served as infected, receiving intraperitoneally 3·3×10(7) trypomastigotes/each. Blood collection was performed at days 60 and 120 post-infection (PI) in order to evaluate the hemogram, blood activity of acetylcholinesterase, and serum butyrylcholinesterase and ADA activities. Hematological parameters did not differ between groups. A significant increase (P<0·05) of acetylcholinesterase activity was observed in blood while butyrylcholinesterase had a significant reduction (P<0·01) in serum of infected rats at days 60 and 120 PI. ADA activity in serum showed an inhibition in infected animals when compared to non-infected at day 120 PI. Based on these results, it is possible to conclude that the activity of cholinesterases and ADA were changed in animals infected with T. cruzi. The possible causes of these alterations will be discussed in this paper.


Subject(s)
Adenosine Deaminase/blood , Antibodies, Protozoan/immunology , Antigens, Protozoan/immunology , Chagas Disease/immunology , Cholinesterases/blood , Heart/parasitology , Trypanosoma cruzi/pathogenicity , Animals , Chagas Disease/enzymology , Male , Motor Activity , Rats
16.
Opt Express ; 19(10): 9111-7, 2011 May 09.
Article in English | MEDLINE | ID: mdl-21643165

ABSTRACT

We implement dispersion-tolerant and time-gating-free all-optical OFDM transmission using a photonic-integrated discrete Fourier transform (DFT) device. We show that 35-Gb/s OFDM data having near-unity spectral efficiency can be transmitted all-optically with 1-dB dispersion margin of ~1000 ps/nm. The passive-optical DFT circuit is implemented using multi-mode interference (MMI) couplers on a high index-contrast silica integrated-optic platform. We also propose a photonic DFT circuit based on an NxN MMI device capable of simultaneous channelization of OFDM signals into N subcarriers.

17.
Gastrointest Endosc ; 73(4): 682-90, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21292262

ABSTRACT

BACKGROUND: Radiofrequency ablation (RFA) is safe and effective for eradicating Barrett's esophagus (BE) and BE-associated early neoplasia. Most RFA studies have limited the baseline length of BE (<10 cm), and therefore little is known about RFA for longer BE. OBJECTIVE: To assess the safety and efficacy of RFA with or without prior endoscopic resection (ER) for BE ≥ 10 cm containing neoplasia. DESIGN: Prospective trial. SETTING: Two tertiary-care centers. PATIENTS: This study involved consecutive patients with BE ≥ 10 cm with early neoplasia. INTERVENTION: Focal ER for visible abnormalities, followed by a maximum of 2 circumferential and 3 focal RFA procedures every 2 to 3 months until complete remission. MAIN OUTCOME MEASUREMENTS: Complete remission, defined as endoscopic resolution of BE and no intestinal metaplasia (CR-IM) or neoplasia (CR-neoplasia) in biopsy specimens. RESULTS: Of the 26 patients included, 18 underwent ER for visible abnormalities before RFA. The ER specimens showed early cancer in 11, high-grade intraepithelial neoplasia (HGIN) in 6, and low-grade intraepithelial neoplasia (LGIN) in 1. The worst residual histology, before RFA and after any ER, was HGIN in 16 patients and LGIN in 10 patients. CR-neoplasia and CR-IM were achieved in 83% (95% confidence interval [CI], 63%-95%) and 79% (95% CI, 58%-93%), respectively. None of the patients had fatal or severe complications and 15% (95% CI, 4%-35%) had moderate complications. During a mean (± standard deviation) follow-up of 29 (± 9.1) months, no neoplasia recurred. LIMITATIONS: Tertiary-care center, short follow-up. CONCLUSION: ER for visible abnormalities, followed by RFA of residual BE is a safe and effective treatment for BE ≥ 10 cm containing neoplasia, with a low chance of recurrence of neoplasia or BE during follow-up.


Subject(s)
Barrett Esophagus/surgery , Catheter Ablation/methods , Early Diagnosis , Esophageal Neoplasms/surgery , Esophagectomy/methods , Esophagoscopy/methods , Aged , Barrett Esophagus/pathology , Biopsy , Esophageal Neoplasms/pathology , Female , Follow-Up Studies , Humans , Male , Prospective Studies , Treatment Outcome
18.
Opt Express ; 19(26): B811-6, 2011 Dec 12.
Article in English | MEDLINE | ID: mdl-22274108

ABSTRACT

We propose that the optical OFDM technique using all optical discrete Fourier transform (DFT) has potential as a viable alternative for upgrading long-haul optical transmission systems towards 100-Gb/s. We demonstrate transmission of 35-Gb/s (7 x 5 Gb/s NRZ-OOK) all-optical OFDM signal over ~2000-km dispersion-managed span without using tunable dispersion compensation and time gating. We achieve bit error ratio of 1.2x10(-3) (7x10(-3)) for transmission over 1980-km (2310-km) all-EDFA amplified span consisting of standard single mode fiber (SSMF) and dispersion compensating fiber (DCF). We also study the nonlinear penalty impacting the all-optical OFDM transmission and discuss potential method for its mitigation.

19.
Opt Express ; 17(21): 19062-6, 2009 Oct 12.
Article in English | MEDLINE | ID: mdl-20372642

ABSTRACT

We propose a method for increased-speed all-optical XOR operation using semiconductor optical amplifiers. We demonstrate XOR and XNOR operations at 86.4 Gb/s using a pair of photonic-integrated semiconductor optical amplifier Mach-Zehnder interferometers.

20.
Proc AMIA Symp ; : 830-4, 2002.
Article in English | MEDLINE | ID: mdl-12463941

ABSTRACT

Since 1984 the French Communicable Disease Network (FCDN) collects and analyses epidemiological information obtained online from a team of "Sentinel General Practitioners" (SGPs). It redistributes this information in the form of standardised weekly incidence estimates. These weekly estimates now appear on the Internet and are the basis for issuing alerts of influenza epidemics. We postulate that day to day estimations would be highly desirable to achieve timely detection of the actual onset of the epidemic, a need dramatically underscored by the emergence of bioterrorism. The present paper suggests the feasibility of reconstructing daily epidemiological information using local smoothing with a suitable spline function to obtain short latency alert messages.


Subject(s)
Influenza, Human/epidemiology , Population Surveillance , Algorithms , Communicable Diseases/epidemiology , Disease Outbreaks , France/epidemiology , Geographic Information Systems , Humans , Incidence , Internet , Population Surveillance/methods
SELECTION OF CITATIONS
SEARCH DETAIL
...