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1.
Clin Exp Allergy ; 48(3): 297-305, 2018 03.
Article in English | MEDLINE | ID: mdl-29168291

ABSTRACT

BACKGROUND: Genetic studies of eczema have identified many genes, which explain only 14% of the heritability. Missing heritability may be partly due to ignored gene-gene (G-G) interactions. OBJECTIVE: Our aim was to detect new interacting genes involved in eczema. METHODS: The search for G-G interaction in eczema was conducted using a two-step approach, which included as a first step, a biological selection of genes, which are involved either in the skin or epidermis development or in the collagen metabolism, and as a second step, an interaction analysis of the selected genes. Analyses were carried out at both SNP and gene levels in three asthma-ascertained family samples: the discovery dataset of 388 EGEA (Epidemiological study on the Genetics and Environment of Asthma) families and the two replication datasets of 253 SLSJ (Saguenay-Lac-Saint-Jean) families and 207 MRCA (Medical Research Council) families. RESULTS: One pair of SNPs, rs2287807 in COL5A3 and rs17576 in MMP9, that were detected in EGEA at P ≤ 10-5 showed significant interaction by meta-analysis of EGEA, SLSJ and MRCA samples (P = 1.1 × 10-8 under the significant threshold of 10-7 ). Gene-based analysis confirmed strong interaction between COL5A3 and MMP9 (P = 4 × 10-8 under the significant threshold of 4 × 10-6 ) by meta-analysis of the three datasets. When stratifying the data on asthma, this interaction remained in both groups of asthmatic and non-asthmatic subjects. CONCLUSION: This study identified significant interaction between two new genes, COL5A3 and MMP9, which may be accounted for by a degradation of COL5A3 by MMP9 influencing eczema susceptibility. Further confirmation of this interaction as well as functional studies is needed to better understand the role of these genes in eczema.


Subject(s)
Collagen Type V/genetics , Eczema/genetics , Epistasis, Genetic/genetics , Genetic Predisposition to Disease/genetics , Matrix Metalloproteinase 9/genetics , Adult , Aged , Female , Genotype , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide
2.
Nat Commun ; 8(1): 1408, 2017 11 10.
Article in English | MEDLINE | ID: mdl-29123117

ABSTRACT

The internal structure of nucleons (protons and neutrons) remains one of the greatest outstanding problems in modern nuclear physics. By scattering high-energy electrons off a proton we are able to resolve its fundamental constituents and probe their momenta and positions. Here we investigate the dynamics of quarks and gluons inside nucleons using deeply virtual Compton scattering (DVCS)-a highly virtual photon scatters off the proton, which subsequently radiates a photon. DVCS interferes with the Bethe-Heitler (BH) process, where the photon is emitted by the electron rather than the proton. We report herein the full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the regime where the scattering is expected to occur off a single quark, measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.

3.
Phys Rev Lett ; 118(22): 222002, 2017 Jun 02.
Article in English | MEDLINE | ID: mdl-28621966

ABSTRACT

We report the first longitudinal-transverse separation of the deeply virtual exclusive π^{0} electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure functions dσ_{L}/dt, dσ_{T}/dt, dσ_{LT}/dt, and dσ_{TT}/dt are extracted as a function of the momentum transfer to the recoil system at Q^{2}=1.75 GeV^{2} and x_{B}=0.36. The ed→edπ^{0} cross sections are found compatible with the small values expected from theoretical models. The en→enπ^{0} cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity generalized parton distributions of the nucleon. By combining these results with previous measurements of π^{0} electroproduction off the proton, we present a flavor decomposition of the u and d quark contributions to the cross section.

4.
Sci Rep ; 7(1): 938, 2017 04 20.
Article in English | MEDLINE | ID: mdl-28428554

ABSTRACT

The number of genetic factors associated with asthma remains limited. To identify new genes with an undetected individual effect but collectively influencing asthma risk, we conducted a network-assisted analysis that integrates outcomes of genome-wide association studies (GWAS) and protein-protein interaction networks. We used two GWAS datasets, each consisting of the results of a meta-analysis of nine childhood-onset asthma GWASs (5,924 and 6,043 subjects, respectively). We developed a novel method to compute gene-level P-values (fastCGP), and proposed a parallel dense-module search and cross-selection strategy to identify an asthma-associated gene module. We identified a module of 91 genes with a significant joint effect on childhood-onset asthma (P < 10-5). This module contained a core subnetwork including genes at known asthma loci and five peripheral subnetworks including relevant candidates. Notably, the core genes were connected to APP (encoding amyloid beta precursor protein), a major player in Alzheimer's disease that is known to have immune and inflammatory components. Functional analysis of the module genes revealed four gene clusters involved in innate and adaptive immunity, chemotaxis, cell-adhesion and transcription regulation, which are biologically meaningful processes that may underlie asthma risk. Our findings provide important clues for future research into asthma aetiology.


Subject(s)
Asthma/genetics , Gene Regulatory Networks , Protein Interaction Maps , Age of Onset , Amyloid beta-Protein Precursor/genetics , Asthma/pathology , Child , Genome-Wide Association Study , Humans
5.
Nat Commun ; 7: 13231, 2016 10 24.
Article in English | MEDLINE | ID: mdl-27775037

ABSTRACT

CdTe thin-film solar cells are now the main industrially established alternative to silicon-based photovoltaics. These cells remain reliant on the so-called chloride activation step in order to achieve high conversion efficiencies. Here, by comparison of effective and ineffective chloride treatments, we show the main role of the chloride process to be the modification of grain boundaries through chlorine accumulation, which leads an increase in the carrier lifetime. It is also demonstrated that while improvements in fill factor and short circuit current may be achieved through use of the ineffective chlorides, or indeed simple air annealing, voltage improvement is linked directly to chlorine incorporation at the grain boundaries. This suggests that focus on improved or more controlled grain boundary treatments may provide a route to achieving higher cell voltages and thus efficiencies.

6.
Phys Rev Lett ; 117(26): 262001, 2016 Dec 23.
Article in English | MEDLINE | ID: mdl-28059549

ABSTRACT

We present deeply virtual π^{0} electroproduction cross-section measurements at x_{B}=0.36 and three different Q^{2} values ranging from 1.5 to 2 GeV^{2}, obtained from Jefferson Lab Hall A experiment E07-007. The Rosenbluth technique is used to separate the longitudinal and transverse responses. Results demonstrate that the cross section is dominated by its transverse component and, thus, is far from the asymptotic limit predicted by perturbative quantum chromodynamics. Nonetheless, an indication of a nonzero longitudinal contribution is provided by the measured interference term σ_{LT}. Results are compared with several models based on the leading-twist approach of generalized parton distributions (GPDs). In particular, a fair agreement is obtained with models in which the scattering amplitude includes convolution terms of chiral-odd (transversity) GPDs of the nucleon with the twist-3 pion distribution amplitude. This experiment, together with previous extensive unseparated measurements, provides strong support to the exciting idea that transversity GPDs can be accessed via neutral pion electroproduction in the high-Q^{2} regime.

7.
Clin Exp Allergy ; 45(4): 797-806, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25431337

ABSTRACT

BACKGROUND: Exhaled nitric oxide (FeNO) is a biomarker for eosinophilic inflammation in the airways and for responsiveness to corticosteroids in asthmatics. OBJECTIVE: We sought to identify in adults the genetic determinants of fractional exhaled nitric oxide (FeNO) levels and to assess whether environmental and disease-related factors influence these associations. METHODS: We performed a genome-wide association study of FeNO through meta-analysis of two independent discovery samples of European ancestry: the outbred EGEA study (French Epidemiological study on the Genetics and Environment of Asthma, N = 610 adults) and the Hutterites (N = 601 adults), a founder population living on communal farms. Replication of main findings was assessed in adults from an isolated village in Sardinia (Talana study, N = 450). We then investigated the influence of asthma, atopy and tobacco smoke exposure on these genetic associations, and whether they were also associated with FeNO values in children of the EAGLE (EArly Genetics & Lifecourse Epidemiology, N = 8858) consortium. RESULTS: We detected a common variant in RAB27A (rs2444043) associated with FeNO that reached the genome-wide significant level (P = 1.6 × 10(-7) ) in the combined discovery and replication adult data sets. This SNP belongs to member of RAS oncogene family (RAB27A) and was associated with an expression quantitative trait locus for RAB27A in lymphoblastoid cell lines from asthmatics. A second suggestive locus (rs2194437, P = 8.9 × 10(-7) ) located nearby the sodium/calcium exchanger 1 (SLC8A1) was mainly detected in atopic subjects and influenced by inhaled corticosteroid use. These two loci were not associated with childhood FeNO values. CONCLUSIONS AND CLINICAL RELEVANCE: This study identified a common variant located in RAB27A gene influencing FeNO levels specifically in adults and with a biological relevance to the regulation of FeNO levels. This study provides new insight into the biological mechanisms underlying FeNO levels in adults.


Subject(s)
Genetic Association Studies , Genetic Variation , Nitric Oxide , rab GTP-Binding Proteins/genetics , Adult , Alleles , Asthma/genetics , Asthma/immunology , Asthma/metabolism , Biomarkers , Chromosome Mapping , Exhalation , Female , Genome-Wide Association Study , Genotype , Humans , Male , Meta-Analysis as Topic , Middle Aged , Phenotype , Polymorphism, Single Nucleotide , Quantitative Trait Loci , Risk Factors , Young Adult , rab27 GTP-Binding Proteins
8.
Arthritis Care Res (Hoboken) ; 64(5): 773-9, 2012 May.
Article in English | MEDLINE | ID: mdl-22232128

ABSTRACT

OBJECTIVE: Various methods are utilized in daily practice to obtain optimal information on effusion in the knee. Our aim is to investigate which scanning position provides the best information about synovial fluid in the knee by using ultrasound and to evaluate the magnitude of difference for measuring synovial fluid in 3 major recesses (suprapatellar, medial parapatellar, and lateral parapatellar) of the knee according to various degrees of flexion. METHODS: Sonographers in 14 European centers documented bilateral knee joint ultrasound examinations on a total of 148 knee joints. The largest sagittal diameter of fluid was measured in scans corresponding to the 3 major recesses at different (0°, 15°, 30°, 45°, 60°, and 90°) degrees of flexion of the knee. The difference of measurement of effusion according to transducer position, knee position, and the interaction between them was investigated by analysis of variance followed by Tukey's test. RESULTS: No correlation was noted between patient characteristics and ultrasound detection of effusion. The sagittal diameter of synovial fluid in all 3 recesses was greatest at 30° flexion. Analysis of variance and Tukey's test revealed that the suprapatellar scan and 30° flexion is the best combination for detecting effusion as confirmed by receiver operator characteristic curve analysis. CONCLUSION: The suprapatellar scan of the knee in 30° flexion was the most sensitive position to detect fluid in knee joints. Sagittal diameter of fluid in all 3 recesses increased with the knee in the 30° flexed position as compared to the extended position.


Subject(s)
Knee Joint/diagnostic imaging , Knee Joint/physiopathology , Range of Motion, Articular/physiology , Synovial Fluid/diagnostic imaging , Adult , Aged , Aged, 80 and over , Female , Humans , Internationality , Male , Middle Aged , Ultrasonography , Young Adult
9.
Ultraschall Med ; 33(7): E173-E178, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22194046

ABSTRACT

PURPOSE: To investigate which knee and probe position best identifies knee inflammation and to determine a cut-off level for abnormal synovial effusion. MATERIALS AND METHODS: 18 experienced sonographers (all rheumatologists) performed ultrasound examinations of the knee joint in patients with knee symptoms and in healthy controls. Each sonographer performed longitudinal suprapatellar ultrasound scans using 9 different configurations at each knee: Midline, parapatallar lateral and parapatellar medial from midline in neutral position (0°) with and without quadriceps muscle contraction and in 30° flexion of the knee. The presence of synovial effusion (SE), the effusion measured in millimeters and the presence of synovial hypertrophy (SH) was noted. RESULTS: A total of 298 knees of 149 subjects (129 patients and 20 controls) were examined. The detection of SH is more sensitive and specific than the detection of SE, independently of the knee and probe position, for the final diagnosis of abnormality. The detection of both synovial hypertrophy and effusion in the knee in neutral position (0°) with quadriceps contraction and with the probe in the midline position, are the best independent predictors for knee abnormalities. Knee effusion > 3.2 mm measured with the probe in the lateral aspect of the knee is the best diagnostic characteristics for predicting pathological SE. CONCLUSION: The best combination for detecting SH and SE is obtained by placing the probe in the midline position with the knee in 0° with quadriceps contraction. A cut-off value for pathological effusion may be obtained in the lateral aspect of the knee.


Subject(s)
Arthritis, Rheumatoid/diagnostic imaging , Arthritis/diagnostic imaging , Osteoarthritis, Knee/diagnostic imaging , Patient Positioning , Synovial Fluid/diagnostic imaging , Adult , Aged , Aged, 80 and over , Female , Humans , Hypertrophy , Knee Joint/diagnostic imaging , Male , Middle Aged , Patella/diagnostic imaging , Range of Motion, Articular/physiology , Reference Values , Sensitivity and Specificity , Synovial Membrane/diagnostic imaging , Synovial Membrane/pathology , Ultrasonography , Young Adult
10.
J Helminthol ; 81(4): 369-76, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18039414

ABSTRACT

In the Jura mountains, Plateau and Alps of western Switzerland important variations in the prevalence of Echinococcus multilocularis infection in red foxes were observed between geographical areas from 1990 to 1995. The Jura mountains and the Plateau had higher mean prevalence levels than the Alps with 30.6, 32.4 and 18.8%, respectively. The highest rate was recorded in the Plateau in the canton of Fribourg with a prevalence of 52.3%. The prevalence of E. multilocularis infection in foxes in the alpine canton of Valais was the lowest (7.1%). Juvenile foxes were found to be more susceptible to E. multilocularis than adults. Adult foxes were less heavily infected in summer and autumn, while the prevalence in juveniles (less than 1 year old) increased between the spring and winter, when they are more than 6 months old. The retrospective data relate to the beginning of the 1990s, since when a drastic prevalence increase of E. multilocularis infection in foxes has occurred in several regions of Europe. Nevertheless, the study is a major contribution to the epidemiological situation of E. multilocularis in central Europe, in that it contains valuable information on spatial distribution and seasonal differences in different age groups of foxes.


Subject(s)
Echinococcosis/veterinary , Echinococcus multilocularis/isolation & purification , Foxes/parasitology , Age Factors , Animals , Echinococcosis/epidemiology , Seasons , Switzerland/epidemiology
11.
Vaccine ; 25(17): 3284-92, 2007 Apr 30.
Article in English | MEDLINE | ID: mdl-17270322

ABSTRACT

Iris is a specific elastase inhibitor expressed in the salivary glands of the hard tick Ixodes ricinus. It belongs to the superfamily of serpins and interferes with both haemostasis and the immune response of the host. In this study, we first show that Iris is expressed in nymphs but not in the female midgut nor in males. We also show that Iris is present in the saliva. To examine its potency as anti-tick vaccine candidate, we set up three models of I. ricinus infestation on immunized animals: nymphs on mice, and adults and nymphs on rabbits. We report the rise of neutralizing antibodies following immunization of rabbits and mice. This comes with a significant protective immunity against ticks in rabbits only, resulting in a 30% mortality rate and a diminution of weight gain in both nymphs and adults and a prolongation of blood feeding time in adults. This is the first report on an anti-tick vaccine trial on I. ricinus using a protein able to interact with both host immunity and haemostasis, as a vaccinating antigen.


Subject(s)
Ixodes/immunology , Serpins/immunology , Tick Infestations/prevention & control , Animals , Blotting, Western , Female , Immunoglobulin G/blood , Mice , Mice, Inbred BALB C , Rabbits , Serpins/analysis , Vaccination
12.
Phys Rev Lett ; 99(24): 242501, 2007 Dec 14.
Article in English | MEDLINE | ID: mdl-18233443

ABSTRACT

The present experiment exploits the interference between the deeply virtual Compton scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D(e,e'gamma)X cross section measured at Q2=1.9 GeV2 and xB=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to E_{q}, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.

13.
Phys Rev Lett ; 97(26): 262002, 2006 Dec 31.
Article in English | MEDLINE | ID: mdl-17280421

ABSTRACT

We present the first measurements of the e[over -->]p-->epgamma cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q(2) dependence (from 1.5 to 2.3 GeV(2)) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q(2). The helicity-independent cross section is also measured at Q(2)=2.3 GeV(2). We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation.

14.
Parasitology ; 129 Suppl: S161-76, 2004.
Article in English | MEDLINE | ID: mdl-15940820

ABSTRACT

Ticks are of vast medical and veterinary public health importance due to direct damage caused by feeding and their roles in transmitting well known and emerging infectious agents. Ticks and tick-borne pathogens stimulate the immune system of the host. Those immune interactions are of importance in tick biology, pathogen transmission and control of ticks and tick-borne diseases. Both innate and specific acquired immune defenses are involved in the responses of vertebrate hosts to infestation. Ticks have evolved countermeasures to circumvent host immune defenses. This review addresses the immunobiology of the tick-host interface from the perspectives of the pharmacology of tick saliva; relationship of tick saliva to pathogen transmission; host immune responses to infestation; tick modulation of host immune defences; and genomic/proteomic strategies for studying tick salivary gland molecules.


Subject(s)
Arachnid Vectors/immunology , Tick Infestations/immunology , Tick-Borne Diseases/immunology , Ticks/immunology , Animals , Arachnid Vectors/genetics , Genomics/trends , Host-Parasite Interactions/genetics , Host-Parasite Interactions/immunology , Humans , Proteomics/trends , Saliva/immunology , Tick-Borne Diseases/transmission , Ticks/genetics
15.
Parasite Immunol ; 23(2): 61-9, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11240897

ABSTRACT

BALB/c mice were infested with Ixodes ricinus larvae, nymphs or adults. Expression of IL-4 and IFN-gamma mRNA in axillary and brachial draining lymph node cells were measured by competitive quantitative reverse transcription-polymerase chain reaction 9 days after the beginning of primary-infestation. IL-4 mRNA was always higher than that of IFN-gamma mRNA for all tick instars. Moreover, IL-4 mRNA expression progressively increased during nymphal primary-infestation with a high burst of expression 7 days after the beginning of infestation. No evolution of IFN-gamma mRNA expression was detected. Draining lymph node cells of infested BALB/c produced higher level of IL-4 than IFN-gamma following in vitro restimulation with adult tick saliva, salivary gland extract (SGE) or with five selected different chromatographic fractions of SGE. Anti-tick IgG1 antibodies but no IgG2a were detected in BALB/c pluri-infested with I. ricinus nymphs, which confirmed the Th2 polarization of the immune response.


Subject(s)
Ixodes/immunology , Th2 Cells/immunology , Tick Infestations/immunology , Animals , Antibodies/analysis , Antigens/administration & dosage , Antigens/immunology , Cells, Cultured , Chromatography , Enzyme-Linked Immunosorbent Assay , Female , Immunization , Immunoblotting , Immunoglobulin G/analysis , Interferon-gamma/biosynthesis , Interferon-gamma/genetics , Interleukin-4/biosynthesis , Interleukin-4/genetics , Lymph Nodes/immunology , Male , Mice , Mice, Inbred BALB C , RNA, Messenger/biosynthesis , Reverse Transcriptase Polymerase Chain Reaction , Saliva/immunology , Salivary Glands/immunology , Tissue Extracts/immunology
16.
Parasitol Res ; 86(6): 491-6, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10894476

ABSTRACT

Mice were tolerant to tick bites during three infestations with nymphs of Ixodes ricinus infected with Borrelia burgdorferi sensu stricto. To determine whether tick bites influence the immune response against B. burgdorferi, we examined the production of cytokines IL-4 and IFN-gamma by lymph node cells of BALB/c mice and IL-4 deficient BALB/c mice after tick inoculation versus syringe inoculation of B. burgdorferi. We also measured IgG2a anti-borrelial antibodies and total IgE in these mice. Results showed that BALB/c mice developed a Th2 immune response against B. burgdorferi after tick inoculation and a mixed Th1/Th2 response after syringe inoculation of B. burgdorferi. IL-4 deficient mice produced a Th1 immune response in both cases. IL-4 produced following tick bites greatly decreased the production of anti-borrelial IgG2a antibodies by comparison with the production of anti-borrelial IgG2a antibodies produced following syringe injection of B. burgdorferi.


Subject(s)
Antibodies, Bacterial/blood , Borrelia burgdorferi , Cytokines/biosynthesis , Immunoglobulin Isotypes/blood , Ixodes/parasitology , Lyme Disease/immunology , Animals , Arachnid Vectors/parasitology , Borrelia burgdorferi Group/immunology , Enzyme-Linked Immunosorbent Assay , Feeding Behavior , Female , Immunoglobulin E/blood , Immunoglobulin G/blood , Interferon-gamma/biosynthesis , Interleukin-4/biosynthesis , Lyme Disease/transmission , Lymph Nodes/cytology , Lymph Nodes/immunology , Mice , Mice, Inbred BALB C , Nymph/parasitology
17.
J Clin Microbiol ; 38(3): 1002-7, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10698987

ABSTRACT

The presence of granulocytic ehrlichiae was demonstrated by PCR in Ixodes ricinus ticks and wild small mammals in Switzerland in two areas of endemicity for bovine ehrlichiosis. Six ticks (three females and three nymphs) (1.4%) of 417 I. ricinus ticks collected by flagging vegetation contained ehrlichial DNA. A total of 201 small mammals from five species, wood mouse (Apodemus sylvaticus), yellow-necked mouse (Apodemus flavicollis), earth vole (Pitymys subterraneus), bank vole (Clethrionomys glareolus), and common shrew (Sorex araneus), were trapped. The analysis of I. ricinus ticks [corrected] collected on 116 small mammals showed that nine C. glareolus voles and two A. sylvaticus mice hosted infected tick larvae. In these rodents, granulocytic ehrlichia infection was also detected in blood, spleen, liver, and ear samples. Further examinations of 190 small mammals without ticks or with noninfected ticks showed the presence of ehrlichial DNA in spleen and other tissues from six additional C. glareolus, three A. flavicollis, and one S. araneus mammals. This study suggests that A. sylvaticus, A. flavicollis, S. araneus, and particularly C. glareolus are likely to be natural reservoirs for granulocytic ehrlichiae. Partial 16S rRNA gene sequences of granulocytic ehrlichiae from ticks and rodents showed a high degree of homology (99 to 100%) with granulocytic ehrlichiae isolated from humans. In contrast, groESL heat shock operon sequence analysis showed a strong divergence (approximately 5%) between the sequences in samples derived from rodents and those derived from samples from questing ticks or from other published ehrlichia sequences. Dual infections with granulocytic ehrlichia and Borrelia burgdorferi were found in ticks and small mammals.


Subject(s)
Ehrlichia/isolation & purification , Ehrlichiosis/veterinary , Ixodes/microbiology , Mammals/parasitology , Animals , Animals, Wild , Arvicolinae/parasitology , Borrelia burgdorferi Group/isolation & purification , Cattle , DNA, Bacterial/analysis , Ehrlichia/classification , Ehrlichia/genetics , Ehrlichiosis/diagnosis , Female , Geography , Humans , Larva , Male , Molecular Sequence Data , Muridae/parasitology , Polymerase Chain Reaction , Shrews/parasitology , Switzerland
18.
Biochim Biophys Acta ; 1478(1): 51-60, 2000 Mar 16.
Article in English | MEDLINE | ID: mdl-10719174

ABSTRACT

We have investigated the effects of different biologically active components from natural products, including green tea polyphenols (GTP), resveratrol, genistein and organosulfur compounds from garlic, on matrix metalloproteinase (MMP)-2, MMP-9 and MMP-12 activities. GTP caused the strongest inhibition of the three enzymes, as measured by fluorescence assays using gelatin or elastin as substrates. The inhibition of MMP-2 and MMP-9 caused by GTP was confirmed by gelatin zymography and was observed for MMPs associated with both various rat tissues and human brain tumors (glioblastoma and pituitary tumors). The activities of MMPs were also measured in the presence of various catechins isolated from green tea including (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate(ECG), (-)-epigallocatechin (EGC), (-)-epicatechin (EC) and (+)-catechin (C). The most potent inhibitors of these activities, as measured by fluorescence and by gelatin or casein zymography, were EGCG and ECG. GTP and the different catechins had no effect on pancreatic elastase, suggesting that the effects of these molecules on MMP activities are specific. Furthermore, in vitro activation of proMMP-2 secreted from the glioblastomas cell line U-87 by the lectin concanavalin A was completely inhibited by GTP and specifically by EGCG. These results indicate that catechins from green tea inhibit MMP activities and proMMP-2 activation.


Subject(s)
Catechin/analogs & derivatives , Matrix Metalloproteinase Inhibitors , Tea , Animals , Catechin/chemistry , Catechin/pharmacology , Cell Line , Concanavalin A , Cricetinae , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Enzyme Precursors/antagonists & inhibitors , Gelatinases/antagonists & inhibitors , Guanosine Triphosphate/pharmacology , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Metalloendopeptidases/antagonists & inhibitors , Mice , Molecular Structure , Swine
19.
Am J Physiol ; 277(6): F832-40, 1999 12.
Article in English | MEDLINE | ID: mdl-10600929

ABSTRACT

The expression of two members of the ATP-binding cassette family of transport proteins, P-glycoprotein (P-gp) and the canalicular multispecific organic anion transporter (cMOAT or Mrp2), was evaluated in renal brush-border membranes (BBM) and various rat tissues after cisplatin treatment. One administration of cisplatin (5 mg/kg) increased P-gp expression by >200-300% in renal BBM and in crude membranes from liver and intestine. The increase in P-gp expression in the kidney was also detected in photolabeling experiments, suggesting the induction of functional P-gp. cMOAT expression was increased by >10-fold in renal BBM after cisplatin administration, although it had no effect on liver cMOAT expression. The increase in the levels of both proteins was maximal at 2 days after cisplatin treatment and lasted for at least 8 days. These results indicate that a single administration of cisplatin induces overexpression of P-gp and cMOAT in specific tissues. This may be of significant relevance to the design of clinical trials using cisplatin as a single chemotherapeutic agent or in combination with other drugs.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Carrier Proteins/genetics , Cisplatin/pharmacology , Gene Expression Regulation/drug effects , Kidney/drug effects , Animals , Anion Transport Proteins , Brain/metabolism , Capillaries/metabolism , Cell Membrane/metabolism , Cerebrovascular Circulation , Kidney/metabolism , Liver/metabolism , Lung/metabolism , Male , Microvilli/metabolism , Organ Specificity , Rats , Rats, Sprague-Dawley
20.
Schweiz Med Wochenschr ; 129(26): 979-84, 1999 Jul 03.
Article in German | MEDLINE | ID: mdl-10431321

ABSTRACT

AIM: To test sensitivity and specificity of a polymerase chain reaction (PCR) targeting the Borrelia specific outer surface protein (Osp) A gene in synovial fluid for the diagnosis of Lyme arthritis, and thus permit an earlier start to treatment. PATIENTS AND METHODS: Prospectively we examined the synovial fluid of 37 patients with the clinical diagnosis of Lyme arthritis or with other arthropathies of known or unknown origin, searching for the presence of detectable borrelial DNA in both arms of the study. Retrospectively we examined the stored synovial fluid from 50 patients of the Department of Rheumatology of the University Hospital, Berne, with the clinical diagnosis of monarthritis or oligoarthritis of unknown etiology, juvenile chronic arthritis or rheumatoid arthritis. The laboratory biologist was unaware of the clinical diagnosis. RESULTS: In the prospective study no true false positive results were found: of the 28 patients without strong clinical suspicion of Lyme arthritis 27 were PCR negative. In one case with positive PCR for borrelial DNA the diagnosis could not be clarified, Lyme arthritis remaining a possibility. Therefore the specificity in the prospective study was at least 96%. Borrelial DNA in the synovial fluid was found in 5 out of 9 patients with strong clinical suspicion of Lyme arthritis. All 7 patients in this group were new, untreated cases. All the 5 PCR positive results belonged to this group, thus the "sensitivity" of the tested method was 71% in untreated cases of Lyme arthritis. In the retrospective study we found borrelial DNA in the synovial fluid of 2 patients. These 2 patients had gonarthritis of unknown origin. Retrospectively these 2 cases could be diagnosed as Lyme arthritis. CONCLUSION: In cases with clinical suspicion of Lyme arthritis the PCR method targeting a borrelial Osp A gene fragment common to all 3 European genospecies shows very good specificity and in untreated cases acceptable sensitivity. Introduction of the method studied into clinical practice is justified.


Subject(s)
Arthritis/diagnosis , Borrelia burgdorferi Group/isolation & purification , DNA, Bacterial/analysis , Lyme Disease/diagnosis , Synovial Fluid/microbiology , Adolescent , Adult , Arthritis, Rheumatoid/diagnosis , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Polymerase Chain Reaction/methods , Prospective Studies , Reproducibility of Results
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