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1.
Vet Microbiol ; 251: 108910, 2020 Dec.
Article de Anglais | MEDLINE | ID: mdl-33160194

RÉSUMÉ

Mycoplasma haemocanis (Mhc) and "Candidatus Mycoplasma haematoparvum" (CMhp) are the main haemoplasma species known to infect dogs. The aim of this study was to determine the prevalence of haemoplasma species infections in hunting dogs from southern Italy and assess related risk factors. 1,433 hunting dogs living in Campania region were tested by qPCR assay. The prevalence was 19.9 %; 13.1 % for Mhc and 11.4 % for CMhp; 4.6 % showed a coinfection with both haemoplasma species. Statistical analysis revealed living in Salerno province (Mhc: OR 3.72; CMhp: OR 2.74), hound (Mhc: OR 5.26; CMhp: OR 8.46) and mixed breed (Mhc: OR 3.38; CMhp: OR 2.80), rural environment (Mhc: OR 12.58; CMhp: OR 10.38), wild mammal hunting (Mhc: OR 8.73; CMhp: OR 8.32), cohabitation with other animals (Mhc: OR 2.82; CMhp: OR 2.78) and large pack size (Mhc: OR 2.96; CMhp: OR 1.61) as risk factors for haemoplasmas. Male gender (OR 1.44) and tick infestation history (OR 1.40) represented risk factors only for Mhc, while adult age (2-7 years - OR 2.01; > 7 years - OR 1.84) and large body size (OR 1.48) were associated only to CMhp. Mhc infection was significantly associated to Babesia vogeli (p < 0.05) and Hepatozoon canis (p < 0.001), while CMhp with H. canis (p < 0.001). This study adds information on haemoplasma species distribution in hunting dogs in southern Italy. Outdoor lifestyle and contact with wild fauna, through greater exposure to tick infestation, or possibly wounds acquired during hunting or fighting, could be factors contributing to haemoplasma infections.


Sujet(s)
Maladies des chiens/épidémiologie , Infections à Mycoplasma/épidémiologie , Infections à Mycoplasma/médecine vétérinaire , Mycoplasma/génétique , Mycoplasma/isolement et purification , Infestations par les tiques/médecine vétérinaire , Chiens de travail/microbiologie , Animaux , ADN bactérien/génétique , Maladies des chiens/microbiologie , Chiens , Femelle , Italie/épidémiologie , Mâle , Mycoplasma/classification , Mycoplasma/pathogénicité , Prévalence , ARN ribosomique 16S/génétique , Facteurs de risque
2.
Parasitol Res ; 119(9): 3023-3031, 2020 Sep.
Article de Anglais | MEDLINE | ID: mdl-32725320

RÉSUMÉ

Hepatozoon canis is a hemoprotozoan organism that infects domestic and wild carnivores throughout much of Europe. The parasite is mainly transmitted through the ingestion of infected ticks containing mature oocysts. The aims of the present survey were to determine the prevalence of H. canis in hunting dogs living in Southern Italy and to assess potential infection risk factors. DNA extracted from whole blood samples, collected from 1433 apparently healthy dogs living in the Napoli, Avellino, and Salerno provinces of Campania region (Southern Italy), was tested by a quantitative real-time polymerase chain reaction (qPCR) assay to amplify H. canis. Furthermore, the investigated dog population was also screened by qPCR for the presence of Ehrlichia canis, a major tick-borne pathogen in Southern Italy, in order to assess possible co-infections. Two hundred dogs were H. canis PCR-positive, resulting in an overall prevalence of 14.0% (CI 12.2-15.9). Breed category (P < 0.0001), hair coat length (P = 0.015), and province of residence (P < 0.0001) represented significant risk factors for H. canis infection. The presence of H. canis DNA was also significantly associated with E. canis PCR positivity (P < 0.0001). Hunting dogs in Campania region (Southern Italy) are frequently exposed to H. canis, and the infection is potentially associated with close contact with wildlife. Further studies are needed to assess the pathogenic potential of H. canis, as well as the epidemiological relationships between hunting dogs and wild animal populations sharing the same habitats in Southern Italy.


Sujet(s)
Coccidiose/médecine vétérinaire , Maladies des chiens/parasitologie , Eucoccidiida/isolement et purification , Animaux , Coccidiose/parasitologie , Coccidiose/transmission , Maladies des chiens/sang , Maladies des chiens/épidémiologie , Maladies des chiens/transmission , Chiens , Eucoccidiida/génétique , Eucoccidiida/physiologie , Femelle , Italie/épidémiologie , Mâle , Réaction de polymérisation en chaîne , Facteurs de risque , Tiques/parasitologie , Tiques/physiologie
3.
Rev Sci Instrum ; 89(10): 10B109, 2018 Oct.
Article de Anglais | MEDLINE | ID: mdl-30399682

RÉSUMÉ

Great advancements in modern field-reversed configuration (FRC) experiments motivated the development of a 14-chord three-wave far infrared (FIR) laser interferometry and polarimetry diagnostic system, which can provide simultaneous high temporal resolution measurements of density and Faraday rotation profiles with high accuracy. The unique challenges facing FIR diagnostics in high beta FRC plasmas are the extremely small (<0.5°) Faraday rotation angles, and severe laser beam refraction effects due to high density gradient and choice of long wavelength. The diagnostic system design and development are described with methods to overcome the challenges, and initial experimental data are also presented.

4.
Rev Sci Instrum ; 89(10): 10B113, 2018 Oct.
Article de Anglais | MEDLINE | ID: mdl-30399974

RÉSUMÉ

Characterization of the plasma structure and density is critical for the diagnosis and control of C-2W plasma equilibria. To this end, two compact, highly portable, turnkey second harmonic interferometers are used to make measurements with greater flexibility than available from other diagnostics, providing important information in areas otherwise inaccessible to more complicated systems. The systems are based on a fiber-coupled 1064 nm Nd:YAG laser and provide a sensitivity of a few 1018 m-2 with a time resolution of a few microseconds. System upgrades were made to allow for beam paths in excess of 5 m. Initial data from two system configurations are presented, showing plasma translation and merged equilibria.

5.
Vet J ; 226: 6-11, 2017 Aug.
Article de Anglais | MEDLINE | ID: mdl-28911844

RÉSUMÉ

Anaplasma phagocytophilum and Borrelia burgdorferi are both transmitted by Ixodes spp. and are associated with clinical illness in some infected dogs. This study evaluated canine antibody responses to the A. phagocytophilum p44 peptides APH-1 and APH-4 as well as the B. burgdorferi C6 peptide before and after doxycycline treatment. A total of eight dogs were infested with wild-caught I. scapularis for 1 week. Blood was collected prior to tick attachment and from Days 3-77 to 218-302 with doxycycline treatment beginning on Day 218. Blood was assayed for A. phagocytophilum DNA by PCR assay. Sera was assessed for antibodies by immunofluorescent antibody (IFA) test and ELISA. Anaplasma phagocytophilum DNA was amplified from blood of all dogs by Day 7. Antibodies to APH-4 were detected in serum as early as 14days after tick exposure and six dogs had APH-4 antibodies detected 3-7 days before antibodies against APH-1. All dogs were seropositive for A. phagocytophilum from Days 218 to 302. Antibodies to B. burgdorferi were detected in 6/8 dogs beginning 21days after I. scapularis infestation. Among the five dogs that remained seropositive at Day 218, C6 antibody levels declined on average 81% within 84days of initiating treatment. The results suggest that the APH-4 peptide may be more useful than APH-1 for detecting antibodies earlier in the course of an A. phagocytophilum infection. After doxycycline administration, C6 antibody levels but not APH-1 or APH-4 antibody levels decreased, suggesting a treatment effect on C6 antibody production.


Sujet(s)
Anaplasma phagocytophilum/immunologie , Borrelia burgdorferi/immunologie , Maladies des chiens/parasitologie , Ehrlichiose/médecine vétérinaire , Ixodes , Maladie de Lyme/médecine vétérinaire , Infestations par les tiques/médecine vétérinaire , Animaux , Antibactériens/usage thérapeutique , Anticorps antibactériens/sang , Protéines bactériennes/immunologie , Maladies des chiens/immunologie , Chiens , Doxycycline/usage thérapeutique , Ehrlichiose/traitement médicamenteux , Ehrlichiose/immunologie , Ehrlichiose/transmission , Femelle , Maladie de Lyme/traitement médicamenteux , Maladie de Lyme/immunologie , Maladie de Lyme/transmission , Mâle , Peptides/immunologie , Réaction de polymérisation en chaine en temps réel/médecine vétérinaire , Infestations par les tiques/complications , Infestations par les tiques/immunologie
6.
Rev Sci Instrum ; 87(11): 11E128, 2016 Nov.
Article de Anglais | MEDLINE | ID: mdl-27910311

RÉSUMÉ

In the prior C-2 experiment, electron density was measured using a two-color 6-chord CO2/HeNe interferometer. Analysis shows that high-frequency common mode phase noise can be reduced by a factor of 3 by constructing a reference chord. In the system upgrade from C-2 to C-2U a 4-chord far-infrared laser interferometer was developed, which demonstrated superior sensitivity (1 × 1016 m-2 at >1 MHz bandwidth) and solved the under spatial sampling issue of the C-2 interferometer system. Improved density-profile measurement results are presented in this paper, including evidence of fast-ion modified density profile and stabilization of the n = 1 plasma wobble mode.

7.
Rev Sci Instrum ; 87(11): 11E125, 2016 Nov.
Article de Anglais | MEDLINE | ID: mdl-27910420

RÉSUMÉ

A high sensitivity multi-channel far infrared laser diagnostics with switchable interferometry and polarimetry operation modes for the advanced neutral beam-driven C-2U field-reversed configuration (FRC) plasmas is described. The interferometer achieved superior resolution of 1 × 1016 m-2 at >1.5 MHz bandwidth, illustrated by measurement of small amplitude high frequency fluctuations. The polarimetry achieved 0.04° instrument resolution and 0.1° actual resolution in the challenging high density gradient environment with >0.5 MHz bandwidth, making it suitable for weak internal magnetic field measurements in the C-2U plasmas, where the maximum Faraday rotation angle is less than 1°. The polarimetry resolution data is analyzed, and high resolution Faraday rotation data in C-2U is presented together with direct evidences of field reversal in FRC magnetic structure obtained for the first time by a non-perturbative method.

8.
J Vet Intern Med ; 29(2): 552-5, 2015.
Article de Anglais | MEDLINE | ID: mdl-25776536

RÉSUMÉ

BACKGROUND: Ehrlichia ewingii, which causes disease in dogs and people, is the most common Ehrlichia spp. infecting dogs in the United States, but little is known about how long E. ewingii infection persists in dogs. HYPOTHESIS/OBJECTIVES: To evaluate the persistence of natural infection with E. ewingii in dogs. ANIMALS: Four Class A Beagles; no previous exposure to ticks or tick-borne infectious agents. METHODS: Dogs were exposed to ticks by weekly walks through tick habitat in north central Oklahoma; dogs positive for infection with Ehrlichia spp. by sequence-confirmed PCR and peptide-specific serology were evaluated for 733 days (D). Whole blood was collected once weekly for PCR, and serum was collected once monthly for detection of antibodies to Ehrlichia canis (peptide p16), Ehrlichia chaffeensis (indirect fluorescence antibody [IFA] and variable-length PCR target [VLPT]), and E. ewingii (peptide p28). RESULTS: All dogs (4/4) became infected with Ehrlichia spp. as evidenced by seroconversion on IFA to E. chaffeensis (4/4); PCR detection of E. ewingii (4/4) and E. chaffeensis (2/4) DNA using both nested and real-time assays; and presence of specific antibodies to E. ewingii (4/4) and E. chaffeensis (2/4). Infection with E. chaffeensis was not detected after D55. Intermittent E. ewingii rickettsemia persisted in 3 of 4 dogs for as long as 733 days. CONCLUSIONS AND CLINICAL IMPORTANCE: Our data demonstrate that dogs infected with E. ewingii from tick feeding are capable of maintaining infection with this pathogen long-term, and may serve as a reservoir host for the maintenance of E. ewingii in nature.


Sujet(s)
Maladies des chiens/microbiologie , Ehrlichia/immunologie , Ehrlichiose/médecine vétérinaire , Infestations par les tiques/médecine vétérinaire , Animaux , Anticorps antibactériens , Maladies des chiens/sang , Maladies des chiens/étiologie , Chiens , Ehrlichia chaffeensis/immunologie , Ehrlichiose/microbiologie , Technique d'immunofluorescence indirecte , Réaction de polymérisation en chaîne/méthodes , Infestations par les tiques/sang , Infestations par les tiques/complications
9.
J Spec Oper Med ; 14(4): 81-85, 2014.
Article de Anglais | MEDLINE | ID: mdl-25399372

RÉSUMÉ

BACKGROUND: Based on the high tick-borne pathogen results from a 2011 surveillance study in three Colombian cities, an in-depth point prevalence survey was conducted to determine the seroprevalence of tick-borne pathogens at a specific point in time in 70 working dogs, 101 shelter dogs, and 47 client-owned dogs in Barranquilla, Colombia. RESULTS: Of the 218 serum samples, 163 (74%) were positive for Ehrlichia canis and 116 (53%) for Anaplasma platys. Exposure to tick-borne pathogens was highest in shelter and working dogs where more than 90% of the samples were seropositive or positive on polymerase chain reaction for one or more organisms as compared to 51% in client-owned animals. CONCLUSION: Surveillance for exposure to tick-borne pathogens provides vital information necessary to protect and conserve the health of local humans and animals, deployed military service members, and working dogs in various parts of the world. This study and resultant data demonstrate the value of following a broad-based surveillance study with a more specific, focused analysis in an area of concern. This area?s high levels of exposure warrant emphasis by medical planners and advisors on precautionary measures for military dogs, Special Operations Forces personnel, and the local public.


Sujet(s)
Anaplasmose/épidémiologie , Maladies des chiens/épidémiologie , Chiens/microbiologie , Ehrlichiose/médecine vétérinaire , Maladie de Lyme/médecine vétérinaire , Personnel militaire , Animaux de compagnie/microbiologie , Anaplasma , Animaux , Borrelia burgdorferi , Colombie/épidémiologie , Ehrlichia canis , Ehrlichiose/épidémiologie , Surveillance épidémiologique , Maladie de Lyme/épidémiologie , Prévalence , Études séroépidémiologiques
10.
Vet Parasitol ; 206(1-2): 93-8, 2014 Nov 15.
Article de Anglais | MEDLINE | ID: mdl-25218886

RÉSUMÉ

To better understand the efficacy of doxycycline and 10% imidacloprid+2.5% moxidectin (Advantage Multi(®); Bayer Animal Health, Shawnee Mission, Kansas) on immature adult Dirofilaria immitis parasites and the results of antigen tests, 12 healthy, randomly selected dogs were experimentally infected with D. immitis and monitored for 407 days. Two dogs in each of three subgroups of four dogs were each infected with six (total of 6 dogs) or 12 (total of 6 dogs) D. immitis infective third-stage larvae (L3) obtained from infected mosquitoes. Doxycycline (10mg/kg per os twice daily×30 days) and 10% imidacloprid+2.5% moxidectin (1ml/kg by topical application every 30 days) treatment was initiated at 105 (Group A) and 149 (Group B) days post infection (PI) in two groups. One subgroup of two dogs given 6 L3 and one subgroup of two dogs given 12 L3 remained as untreated controls (GroupC). Serum obtained regularly throughout the study was evaluated by ELISA (PetChek(®) Heartworm-PF Antigen Test, IDEXX Laboratories, Inc.) for D. immitis adult circulating antigens. Six of the eight dogs in the treated groups had detectable antigenemia starting between 148 and 240 days post infection, but antigen was not detected in any treated dog at the end of the study. In the control subgroups, the dogs that received 6 L3 had no detectable antigen while the two dogs that received 12 L3 had detectable antigen beginning on Day 180 that persisted until the end of the study. None of the infected dogs had evidence of circulating microfilariae. At necropsy, no heartworms were recovered from the treated dogs, but all dogs in the untreated group had viable adult heartworms. These results indicate that early immature adult worms (3.5 and 5 months of age) of D. immitis were susceptible to a combined treatment regimen of doxycycline and 10% imidacloprid+2.5% moxidectin.


Sujet(s)
Dirofilaria immitis/effets des médicaments et des substances chimiques , Dirofilariose/traitement médicamenteux , Maladies des chiens/traitement médicamenteux , Filaricides/pharmacologie , Filaricides/usage thérapeutique , Animaux , Antigènes d'helminthe/sang , Dirofilariose/diagnostic , Maladies des chiens/diagnostic , Chiens , Doxycycline/pharmacologie , Doxycycline/usage thérapeutique , Association de médicaments/médecine vétérinaire , Femelle , Imidazoles/pharmacologie , Imidazoles/usage thérapeutique , Macrolides/pharmacologie , Macrolides/usage thérapeutique , Mâle , Néonicotinoïdes , Composés nitrés/pharmacologie , Composés nitrés/usage thérapeutique , Répartition aléatoire
12.
Placenta ; 28(8-9): 824-32, 2007.
Article de Anglais | MEDLINE | ID: mdl-17303237

RÉSUMÉ

Water arrives in the mammalian gestation from the maternal circulation across the placenta. It then circulates between the fetal water compartments, including the fetal body compartments, the placenta and the amniotic fluid. Amniotic fluid is created by the flow of fluid from the fetal lung and bladder. A major pathway for amniotic fluid resorption is fetal swallowing; however, in many cases the amounts of fluid produced and absorbed do not balance. A second resorption pathway, the intramembranous pathway (across the amnion to the fetal circulation), has been proposed to explain the maintenance of normal amniotic fluid volume. Amniotic fluid volume is thus a function both of the amount of water transferred to the gestation across the placental membrane, and the flux of water across the amnion. Water flux across biologic membranes may be driven by osmotic or hydrostatic forces; existing data suggest that intramembranous flow in humans is driven by the osmotic difference between the amniotic fluid and the fetal serum. The driving force for placental flow is more controversial, and both forces may be in effect. The mechanism(s) responsible for regulating water flow to and from the amniotic fluid is unknown. In other parts of the body, notably the kidney, water flux is regulated by the expression of aquaporin water channels on the cell membrane. We hypothesize that aquaporins have a role in regulating water flux across both the amnion and the placenta, and present evidence in support of this theory. Current knowledge of gestational water flow is sufficient to allow prediction of fetal outcome when water flow is abnormal, as in twin-twin transfusion syndrome. Further insight into these mechanisms may allow novel treatments for amniotic fluid volume abnormalities with resultant improvement in clinical outcome.


Sujet(s)
Liquide amniotique , Placenta , Amnios/métabolisme , Liquide amniotique/métabolisme , Animaux , Aquaporines/métabolisme , Syndrome de transfusion foeto-foetale/métabolisme , Humains , Placenta/métabolisme
13.
Placenta ; 28(8-9): 816-23, 2007.
Article de Anglais | MEDLINE | ID: mdl-17254633

RÉSUMÉ

Water arrives in the mammalian gestation from the maternal circulation across the placenta. It then circulates between the fetal water compartments, including the fetal body compartments, the placenta and the amniotic fluid. Amniotic fluid is created by the flow of fluid from the fetal lung and bladder. A major pathway for amniotic fluid resorption is fetal swallowing; however in many cases the amounts of fluid produced and absorbed do not balance. A second resorption pathway, the intramembranous pathway (across the amnion to the fetal circulation), has been proposed to explain the maintenance of normal amniotic fluid volume. Amniotic fluid volume is thus a function both of the amount of water transferred to the gestation across the placental membrane, and the flux of water across the amnion. Membrane water flux is a function of the water permeability of the membrane; available data suggests that the amnion is the structure limiting intramembranous water flow. In the placenta, the syncytiotrophoblast is likely to be responsible for limiting water flow across the placenta. In human tissues, placental trophoblast membrane permeability increases with gestational age, suggesting a mechanism for the increased water flow necessary in late gestation. Membrane water flow can be driven by both hydrostatic and osmotic forces. Changes in both osmotic/oncotic and hydrostatic forces in the placenta my alter maternal-fetal water flow. A normal amniotic fluid volume is critical for normal fetal growth and development. The study of amniotic fluid volume regulation may yield important insights into the mechanisms used by the fetus to maintain water homeostasis. Knowledge of these mechanisms may allow novel treatments for amniotic fluid volume abnormalities with resultant improvement in clinical outcome.


Sujet(s)
Liquide amniotique , Eau , Amnios/métabolisme , Liquide amniotique/composition chimique , Animaux , Âge gestationnel , Humains , Placenta/métabolisme , Eau/métabolisme
14.
Placenta ; 28(5-6): 421-8, 2007.
Article de Anglais | MEDLINE | ID: mdl-16870248

RÉSUMÉ

OBJECTIVES: To assess the role of aquaporins (AQPs) in the regulation of amniotic fluid (AF) volume, we determined AF volume and composition and placental and fetal membrane AQP expression throughout the second half of murine gestation. METHODS: Pregnant CD1 mice were sacrificed at e10-19 and AF volume and composition determined. Placenta and fetal membranes were screened for AQP gene expression. AQP gene expression was quantified by real-time RT PCR and protein location determined by immunohistochemistry. Changes in AF volume were correlated with AQP expression. RESULTS: Both membranes and placenta demonstrated expression of AQP1, -3, -8 and -9. Advancing gestation was associated with increased AF volume from e10 to e16, with a marked decrease in AF volume from e16 to e19. By immunohistochemistry, AQP1 was localized to placental vessels and AQP3 to trophoblast. AF volume was negatively correlated with fetal membrane AQP1 and placental AQP1 and AQP9 expression, and positively correlated with placental AQP3 expression. CONCLUSION: Changes in AQPs with advancing gestation, and their correlation with AF volume, suggest a role in mediating placental and membrane water flow and ultimately AF volume. AQP1 appears to regulate fetal membrane water flow, and AQP3 is a likely candidate for the regulation of placental water flow.


Sujet(s)
Liquide amniotique/physiologie , Aquaporines/génétique , Membrane cellulaire/physiologie , Placenta/physiologie , Animaux , Aquaporine-1/génétique , Aquaporine-2/génétique , Aquaporine-3/génétique , Aquaporines/métabolisme , Amorces ADN , Femelle , Régulation de l'expression des gènes au cours du développement , Âge gestationnel , Immunohistochimie , Souris , Placenta/cytologie , Grossesse , RT-PCR
15.
Iowa Orthop J ; 22: 103-7, 2002.
Article de Anglais | MEDLINE | ID: mdl-12180601

RÉSUMÉ

This study evaluated Internet use among orthopaedic patients in a private practice general orthopaedic setting. Of 154 respondents, twenty percent had used the Internet to research their orthopaedic diagnosis. Search rates were lowest for patients with arthritis and highest for patients with disorders of the spine or back. Seventy percent of these patients who had searched had found their searches helpful, and over 50% of patients who had searched had questions raised that they planned to address with their physicians. Of those patients who did search the Internet, none reported concern regarding the credibility of Internet retrieved material.


Sujet(s)
Internet , Maladies ostéomusculaires , Éducation du patient comme sujet/méthodes , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Établissements de soins ambulatoires , Femelle , Humains , Internet/statistiques et données numériques , Mâle , Adulte d'âge moyen , Orthopédie/enseignement et éducation
16.
J Biol Chem ; 276(34): 31613-9, 2001 Aug 24.
Article de Anglais | MEDLINE | ID: mdl-11406634

RÉSUMÉ

The biology of the helminth parasite Schistosoma mansoni is closely integrated with that of its mammalian host. SmRK1, a divergent type I transforming growth factor-beta (TGF-beta) receptor of unknown ligand specificity, was previously identified as a candidate for a receptor that allows schistosomes to respond to host-derived growth factors. The TGF-beta family includes activin, bone morphogenetic proteins (BMPs), and TGF-beta, all of which can play crucial roles in metazoan development. The downstream signaling protein of receptors that respond to TGF-beta and activin is Smad2, whereas the receptors that respond to BMPs signal via Smad1. When a constitutively active mutant of SmRK1 was overexpressed with either schistosome Smad1 (SmSmad1) or SmSmad2, a receptor-dependent modulation of SmSmad phosphorylation and luciferase reporter activity occurred only with SmSmad2. To evaluate potential ligand activators of SmRK1, a chimeric receptor containing the extracellular domain of SmRK1 joined to the intracellular domain of the human type I TGF-beta receptor was used. The chimeric receptor bound radiolabeled TGF-beta and could activate a luciferase reporter gene in response to both TGF-beta 1 and TGF-beta 3 but not BMP7. Confirmatory results were obtained using full-length SmRK1. These experiments implicate TGF-beta as a ligand for SmRK1 and as a potential host-derived regulator of parasite growth and development.


Sujet(s)
Protein-Serine-Threonine Kinases/métabolisme , Schistosoma mansoni/enzymologie , Facteur de croissance transformant bêta/physiologie , Séquence d'acides aminés , Animaux , Activation enzymatique , Humains , Ligands , Mutation , Tests aux précipitines , Liaison aux protéines , Récepteurs TGF-bêta/composition chimique , Similitude de séquences d'acides aminés , Transduction du signal/physiologie
18.
FEBS Lett ; 490(1-2): 65-9, 2001 Feb 09.
Article de Anglais | MEDLINE | ID: mdl-11172812

RÉSUMÉ

Schistosoma mansoni receptor kinase-1 (SmRK1) is a divergent type I transforming growth factor beta (TGFbeta) receptor on the surface of adult parasites. Using the intracellular domain of SmRK1 as bait in a yeast two-hybrid screen we identified an interaction with S. mansoni 14-3-3epsilon. The interaction which is phosphorylation-dependent is not specific to schistosomes since 14-3-3epsilon also binds to TbetaRI, the human type I TGFbeta receptor. 14-3-3epsilon enhances TGFbeta-mediated signaling by TbetaRI and is the first TbetaRI-interacting non-Smad protein identified that positively regulates this receptor. The interaction of 14-3-3epsilon with schistosome and human TbetaRI suggests a conserved, but previously unappreciated, role for this protein in TGFbeta signaling pathways.


Sujet(s)
Récepteur activine, type 1 , Protéines d'helminthes , Protein-Serine-Threonine Kinases/métabolisme , Récepteurs TGF-bêta/métabolisme , Tyrosine 3-monooxygenase/physiologie , Protéines 14-3-3 , Séquence d'acides aminés , Animaux , Cellules COS , ADN complémentaire/métabolisme , Protéines de liaison à l'ADN/métabolisme , Relation dose-effet des médicaments , Humains , Données de séquences moléculaires , Phosphorylation , Plasmides/métabolisme , Tests aux précipitines , Liaison aux protéines , Structure tertiaire des protéines , Récepteur de type I du facteur de croissance transformant bêta , Récepteur de type II du facteur de croissance transformant bêta , Récepteurs de surface cellulaire/métabolisme , Schistosoma/métabolisme , Similitude de séquences d'acides aminés , Transduction du signal , Protéines Smad , Transactivateurs/métabolisme , Techniques de double hybride
19.
J Perinatol ; 21(8): 513-5, 2001 Dec.
Article de Anglais | MEDLINE | ID: mdl-11774010

RÉSUMÉ

OBJECTIVE: Neonatal clavicle fracture has been previously reported to occur in association with shoulder dystocia, suggesting liability on behalf of the obstetrician. However, clavicle fracture is often inconsistently diagnosed, and shoulder dystocia commonly subjectively defined. Using a formal pediatric diagnosis protocol and an objective definition of shoulder dystocia, we sought to determine the incidence, antecedents, and associated morbidities of clavicle fracture and the potential association with shoulder dystocia. STUDY DESIGN: All deliveries at Harbor-UCLA Medical Center complicated by clavicle fracture from January 1996 to March 1999 were studied. Deliveries with clavicle fracture were compared to all vaginal deliveries during this period. RESULTS: Among 4297 deliveries, twenty-six were complicated by clavicle fracture (0.5%). Clavicle fracture was significantly associated with increased maternal age and birth weight greater than 4 kg, though not associated with shoulder dystocia or operative vaginal delivery. Clavicle fracture was associated with meconium passage and with neonatal orthopedic abnormalities. CONCLUSION: Neonatal clavicle fracture is associated with infant birth weight greater than 4 kg, but not with the occurrence of objectively defined shoulder dystocia. However, infants with clavicle fracture may be at increased risk for additional complications.


Sujet(s)
Traumatismes néonatals , Clavicule/traumatismes , Dystocie/complications , Complications du travail obstétrical , Traumatismes néonatals/épidémiologie , Poids de naissance , Dystocie/épidémiologie , Femelle , Fractures osseuses/épidémiologie , Humains , Nouveau-né , Morbidité , Complications du travail obstétrical/épidémiologie , Grossesse , Facteurs de risque
20.
Mol Biochem Parasitol ; 111(1): 131-42, 2000 Nov.
Article de Anglais | MEDLINE | ID: mdl-11087923

RÉSUMÉ

To begin to understand the molecular basis of communication between the parasite Schistosoma mansoni and its mammalian host, we are studying the signaling pathway downstream of S. mansoni receptor kinase-1 (SmRK1), a divergent type I transforming growth factor-beta (TGF-beta) receptor found on the tegumental surface of the parasite. In this study, we have used a homology based PCR approach to clone two S. mansoni Smad (SmSmad) genes; Smads play a pivotal role in the most well understood signaling pathways initiated by the TGF-beta family of ligands in other organisms. Comparison of the amino acid sequences with those of other Smads reveals that the conserved MH1 and MH2 domains of SmSmads show a high degree of identity to homologues in Drosophila. Transcripts for both SmSmads are detected in the same developmental stages as SmRK1, and both are capable of interacting with the intracellular domain of the receptor in vitro. Functional characterization using the human type I TGF-beta receptor further confirms the highly conserved nature of these proteins, as both SmSmads show TGF-beta dependent enhancement of luciferase activity and nuclear translocation in mammalian cells. These data are the first to show a TGF-beta-like receptor/Smad signaling pathway in parasitic helminths and by analogy with other systems, is likely important in regulating schistosome development.


Sujet(s)
Récepteur activine, type 1 , Protéines de liaison à l'ADN/métabolisme , Protéines d'helminthes , Protein-Serine-Threonine Kinases/métabolisme , Récepteurs de surface cellulaire/métabolisme , Récepteurs TGF-bêta/métabolisme , Schistosoma mansoni/métabolisme , Transduction du signal , Transactivateurs/métabolisme , Facteur de croissance transformant bêta/métabolisme , Séquence d'acides aminés , Animaux , Cellules COS , Noyau de la cellule/métabolisme , Clonage moléculaire , Protéines de liaison à l'ADN/composition chimique , Protéines de liaison à l'ADN/génétique , Régulation de l'expression des gènes , Gènes rapporteurs , Ligands , Luciferases/génétique , Données de séquences moléculaires , Réaction de polymérisation en chaîne , Récepteur de type I du facteur de croissance transformant bêta , Récepteur de type II du facteur de croissance transformant bêta , Protéines de fusion recombinantes/métabolisme , Schistosoma mansoni/génétique , Schistosoma mansoni/croissance et développement , Alignement de séquences , Protéines Smad , Protéine Smad2 , Transactivateurs/composition chimique , Transactivateurs/génétique , Transcription génétique , Transfection
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