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2.
Ultrasound Obstet Gynecol ; 63(4): 472-480, 2024 04.
Article de Anglais | MEDLINE | ID: mdl-37743665

RÉSUMÉ

OBJECTIVES: Blood-oxygen-level-dependent (BOLD) magnetic resonance imaging (MRI) facilitates the non-invasive in-vivo evaluation of placental oxygenation. The aims of this study were to identify and quantify a relative BOLD effect in response to hyperoxia in the human placenta and to compare it between pregnancies with and those without fetal growth restriction (FGR). METHODS: This was a prospective multicenter study (NCT02238301) of 19 pregnancies with FGR (estimated fetal weight (EFW) on ultrasound < 5th centile) and 75 non-FGR pregnancies (controls) recruited at two centers in Paris, France. Using a 1.5-Tesla MRI system, the same multi-echo gradient-recalled echo (GRE) sequences were performed at both centers to obtain placental T2* values at baseline and in hyperoxic conditions. The relative BOLD effect was calculated according to the equation 100 × (hyperoxic T2* - baseline T2*)/baseline T2*. Baseline T2* values and relative BOLD effect were compared according to EFW (FGR vs non-FGR), presence/absence of Doppler anomalies and birth weight (small-for-gestational age (SGA) vs non-SGA). RESULTS: We observed a relative BOLD effect in response to hyperoxia in the human placenta (median, 33.8% (interquartile range (IQR), 22.5-48.0%)). The relative BOLD effect did not differ significantly between pregnancies with and those without FGR (median, 34.4% (IQR, 24.1-48.5%) vs 33.7% (22.7-47.4%); P = 0.95). Baseline T2* Z-score adjusted for gestational age at MRI was significantly lower in FGR pregnancies compared with non-FGR pregnancies (median, -1.27 (IQR, -4.87 to -0.10) vs 0.33 (IQR, -0.81 to 1.02); P = 0.001). Baseline T2* Z-score was also significantly lower in those pregnancies that subsequently delivered a SGA neonate (n = 23) compared with those that delivered a non-SGA neonate (n = 62) (median, -0.75 (IQR, -3.48 to 0.29) vs 0.35 (IQR, -0.79 to 1.05); P = 0.01). CONCLUSIONS: Our study confirms a BOLD effect in the human placenta and that baseline T2* values are significantly lower in pregnancies with FGR. Further studies are needed to evaluate whether such parameters may detect placental insufficiency before it has a clinical impact on fetal growth. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Sujet(s)
Hyperoxie , Placenta , Nouveau-né , Grossesse , Femelle , Humains , Placenta/imagerie diagnostique , Études prospectives , Retard de croissance intra-utérin/imagerie diagnostique , Nourrisson petit pour son âge gestationnel , Poids du foetus , Âge gestationnel , Échographie prénatale/méthodes
5.
Gynecol Obstet Fertil Senol ; 47(12): 860-871, 2019 12.
Article de Français | MEDLINE | ID: mdl-31563639

RÉSUMÉ

Abnormalities of umbilical-portal circulation are rare pathologies whose detection points in screening ultrasound are poorly taught. It can present as an unusual looking portal sinus, an abnormal trajectory of the umbilical vein, an anechoic intrahepatic image or more rarely as cardiomegaly. This can also be detected in the context of investigations of fetus with intrauterine growth retardation. Subsequently, the starting point of the diagnostic approach is based on the following dichotomy: does the umbilical vein penetrate or not into the liver, followed by systematic analysis of the trajectory and size of the umbilical-portosystemic vessels with color Doppler. Determining the prognosis of this abnormality, which varies according to the type, is a major challenge and by further studying this disorder in this project, it will help define what surveillance is required and subsequently help decide the most appropriate place for delivery.


Sujet(s)
Circulation sanguine , Veine porte/imagerie diagnostique , Veines ombilicales/imagerie diagnostique , Maladies vasculaires/imagerie diagnostique , Maladies vasculaires/physiopathologie , Femelle , Humains , Grossesse , Échographie prénatale
6.
Cardiovasc Intervent Radiol ; 42(11): 1522-1529, 2019 Nov.
Article de Anglais | MEDLINE | ID: mdl-31482337

RÉSUMÉ

PURPOSE: To compare the accuracy of two-dimensional (2D) versus three-dimensional (3D) image fusion for thoracic endovascular aortic repair (TEVAR) image guidance. MATERIALS AND METHODS: Between December 2016 and March 2018, all eligible patients who underwent TEVAR were prospectively included in a single-center study. Image fusion methods (2D/3D or 3D/3D) were randomly assigned to guide each TEVAR and compared in terms of accuracy, dose area product (DAP), volume of contrast medium injected, fluoroscopy time and procedure time. RESULTS: Thirty-two patients were prospectively included; 18 underwent 2D/3D and 14 underwent 3D/3D TEVAR. The 3D/3D method allowed more accurate positioning of the aortic mask on top of the fluoroscopic images (proximal landing zone error vector: 1.7 ± 3.3 mm) than was achieved by the 2D/3D method (6.1 ± 6.1 mm; p = 0.03). The 3D/3D image fusion method was associated with significantly lower DAP than the 2D/3D method (50.5 ± 30.1 Gy cm2 for 3D/3D vs. 99.5 ± 79.1 Gy cm2 for 2D/3D; p = 0.03). The volume of contrast medium injected was significantly lower for the 3D/3D method than for the 2D/3D method (50.6 ± 22.9 ml vs. 98.4 ± 47.9 ml; p = 0.002). CONCLUSION: Higher image fusion accuracy and lower contrast volume and irradiation dose were observed for 3D/3D image fusion than for 2D/3D during TEVAR. LEVEL OF EVIDENCE: II, Randomized trial.


Sujet(s)
Anévrysme de l'aorte thoracique/imagerie diagnostique , Anévrysme de l'aorte thoracique/chirurgie , Procédures endovasculaires/méthodes , Imagerie tridimensionnelle/méthodes , Imagerie multimodale/méthodes , Radiographie interventionnelle/méthodes , Sujet âgé , Aorte thoracique/imagerie diagnostique , Aorte thoracique/chirurgie , Femelle , Radioscopie/méthodes , Humains , Mâle , Études prospectives , Dose de rayonnement , Reproductibilité des résultats , Résultat thérapeutique
7.
Rev Med Interne ; 32(6): 341-6, 2011 Jun.
Article de Français | MEDLINE | ID: mdl-21269740

RÉSUMÉ

PURPOSE: Wilson's disease (WD) is an inherited disorder of copper metabolism, characterized by the accumulation of copper in the body due to defective biliary copper excretion by hepatocytes. We report a series of 19 patients with WD. PATIENTS AND METHODS: This is a retrospective and descriptive case series of patients with WD followed in two hospitals of North East of France. RESULTS: Eight men and 11 women were studied. Median follow-up time was 16 years, median age at diagnosis was 18 years (range: 5-71 years). Median age at first symptom was 16 years. In addition to four cases diagnosed by familial screening, clinical manifestations at diagnosis were fatigue (n=5), jaundice (n=5), bleeding (n=1), abnormal movement disorders (n=2) and fortuitous (n=2). Cirrhosis was identified in 14 patients, neurological involvement occurred in seven patients and four patients presented with psychiatric disorders. d-penicillamine was the first treatment in 18 patients, discontinued for severe adverse events in seven patients. Trientine or zinc salts were then prescribed. Medical treatment was successful in 13 patients, but five patients underwent liver transplantation. Haemochromatosis was associated in one case, and one patient developed cholangiocarcinoma. CONCLUSION: WD is severe. Medical treatment allows disease control if it is correctly observed. Conversely, worsening with irreversible damage can occur if the treatment is discontinued.


Sujet(s)
Dégénérescence hépatolenticulaire , Adolescent , Adulte , Sujet âgé , Enfant , Enfant d'âge préscolaire , Femelle , Dégénérescence hépatolenticulaire/diagnostic , Dégénérescence hépatolenticulaire/thérapie , Humains , Mâle , Adulte d'âge moyen , Études rétrospectives , Jeune adulte
8.
Med Vet Entomol ; 23(4): 399-409, 2009 Dec.
Article de Anglais | MEDLINE | ID: mdl-19941606

RÉSUMÉ

African swine fever virus (ASFV) infection in adult Ornithodoros porcinus (Murry 1877, sensuWalton 1979) ticks collected from warthog burrows in southern and East Africa was assessed using a duplex genomic amplification approach that is informative with respect to the invertebrate host species and infecting sylvatic cycle virus. DNA extracted from individual ticks was used as template for the simultaneous amplification of a C-terminal 478-bp ASFV p72 gene region and a approximately 313-bp fragment of the tick mitochondrial 16S rRNA gene, under optimized reaction conditions. Within-warthog burrow infection rates ranged from 0% to 43% using this approach, and phylogenetic analysis of 16S gene sequences revealed the presence of three geographically discrete O. porcinus lineages, but no support for subspecies recognition. False negatives are precluded by the inclusion of host species-informative primers that ensure the DNA integrity of cytoplasmically located genome extracts. In addition, infection rate estimates are further improved as false positives arising from carry-over contamination when performing a two-step nested polymerase chain reaction are negated by the one-step approach. Phylogenetic comparison of full-length virus gene sequences with the partial C-terminal p72 gene target confirmed the epidemiological utility of the latter in a sylvatic setting. The method is therefore of particular value in studies assessing the prevalence and diversity of ASFV in relation to the African sylvatic tick vector and holds potential for investigating the role of alternative tick species in virus maintenance and transmission.


Sujet(s)
Virus de la peste porcine africaine/isolement et purification , Peste porcine africaine/virologie , Réservoirs de maladies/médecine vétérinaire , Ornithodoros/virologie , Suidae/parasitologie , Afrique de l'Est/épidémiologie , Peste porcine africaine/épidémiologie , Peste porcine africaine/génétique , Virus de la peste porcine africaine/génétique , Animaux , Séquence nucléotidique , ADN mitochondrial/composition chimique , ADN mitochondrial/génétique , ADN viral/composition chimique , ADN viral/génétique , Réservoirs de maladies/virologie , Variation génétique , Génotype , Données de séquences moléculaires , Phylogenèse , Réaction de polymérisation en chaîne , ARN ribosomique 16S/composition chimique , ARN ribosomique 16S/génétique , Alignement de séquences , Arbres
9.
Am J Med Genet ; 103(2): 138-43, 2001 Oct 01.
Article de Anglais | MEDLINE | ID: mdl-11568920

RÉSUMÉ

Nearly all mutations in the presenilin 1 (PSEN1), presenilin 2 (PSEN2), and amyloid beta precursor protein (APP) genes lead to early-onset Alzheimer disease (EOAD, onset age at or before 65 years). In order to assess the genetic contribution of these genes in a series of Colombian AD cases, we performed a systematic mutation analysis in 11 autosomal dominant, 23 familial, and 42 sporadic AD patients (34% with age of onset < or = 65 years). No APP missense mutations were identified. In three autosomal dominant cases (27.2%), two different PSEN1 missense mutations were identified. Both PSEN1 mutations are missense mutations that occurred in early-onset autosomal AD cases: an I143T mutation in one case (onset age 30 years) and an E280A mutation in two other cases (onset ages 35 and 42 years). In addition, a novel PSEN1 V94M mutation was present in one early-onset AD case without known family history (onset age 53 years) and absent in 53 controls. The E318G polymorphism was present in five AD cases and absent in controls. In PSEN2, two different silent mutations were detected, including one not reported elsewhere (P129). The majority of the Colombian AD cases, predominantly late-onset, were negative for PSEN and APP mutations.


Sujet(s)
Maladie d'Alzheimer/génétique , Protéines/génétique , Âge de début , Sujet âgé , Sujet âgé de 80 ans ou plus , Maladie d'Alzheimer/épidémiologie , Séquence d'acides aminés , Substitution d'acide aminé , Précurseur de la protéine bêta-amyloïde/génétique , Séquence nucléotidique , Colombie/épidémiologie , ADN/composition chimique , ADN/génétique , Analyse de mutations d'ADN , Femelle , Fréquence d'allèle , Humains , Mâle , Protéines membranaires/génétique , Adulte d'âge moyen , Mutation , Mutation ponctuelle , Polymorphisme de restriction , Polymorphisme de conformation simple brin , Préséniline-1 , Préséniline-2
10.
Arq Neuropsiquiatr ; 59(1): 11-7, 2001 Mar.
Article de Anglais | MEDLINE | ID: mdl-11299424

RÉSUMÉ

OBJECTIVE: As the strength of the association between the APOE epsilon4 allele and Alzheimer's disease (AD) varies across ethnic groups, we studied if there was such an association in Colombian patients. METHOD: We performed apolipoprotein E (APOE) genotyping in a clinical sample of 83 unrelated AD patients, predominantly late-onset (>65 yrs) including familial ( n =30) and sporadic AD cases (n= 53) diagnosed according to NINCDS-ADRDA criteria and assessed by a multi-disciplinary team. Control subjects (n = 44) had no significant cognitive impairment by medical interview and neuro-psychological testing. RESULTS: We found a high association (OR= 5.1 95%CI 1.9 -13.6) between APOE epsilon4 and AD, in this series with predominantly late-onset cases with familial aggregation in 24 cases (28.9%). A significant negative association was found between epsilon2 and AD (OR= 0.2 95% CI 0.05-0.75). CONCLUSION: Further population-based surveys in Colombia are warranted to precise a possible dose effect of APOE epsilon4.


Sujet(s)
Maladie d'Alzheimer/génétique , Apolipoprotéines E/génétique , Âge de début , Sujet âgé , Maladie d'Alzheimer/diagnostic , Maladie d'Alzheimer/ethnologie , Apolipoprotéine E4 , Études cas-témoins , Colombie/épidémiologie , Colombie/ethnologie , Femelle , Fréquence d'allèle , Marqueurs génétiques , Génotype , Humains , Amérique latine/épidémiologie , Mâle
11.
Gastroenterol Clin Biol ; 24(6-7): 644-8, 2000.
Article de Français | MEDLINE | ID: mdl-10962388

RÉSUMÉ

AIMS: We aimed to evaluate the effects of several peptides (substance P, VIP, neuropeptide Y, bombesin, glucagon and somatostatin) on the proliferation, migration and differentiation of human endothelial cells and their modulation by an anti-angiogenic factor, endostatin. METHODS: Human endothelial cells (HUVEC) were isolated from umbilical veins. Their proliferation was measured by the incorporation of tritiated thymidine. Their migration was evaluated by using an haptotactic assay performed in Boyden chambers, after metabolic labeling of HUVEC through (35) S-methionin. Differentiation was evaluated as the capacity for HUVEC to form capillaries. RESULTS: Endothelial cell proliferation was increased by neuropeptide Y, bombesin and glucagon. Somatostatin induced a significant decrease in basal and stimulated endothelial cell proliferation. The migration of HUVEC increased in the presence of substance P, VIP, neuropeptide Y, bombesin, glucagon and somatostatin. The number of capillaries was increased by substance P and VIP and decreased by neuropeptide Y, bombesin and somatostatin. Endostatin induced a significant decrease in endothelial cell proliferation in the basal state and after stimulation by neuropeptide Y and bombesin. Endostatin had no additive effect on the anti-proliferative action of somatostatin. CONCLUSIONS: Our results suggest a role for endocrine peptides in the regulation of tumor angiogenesis. The potent anti-angiogenic effect of somatostatin may promote new therapeutic strategies.


Sujet(s)
Différenciation cellulaire/effets des médicaments et des substances chimiques , Division cellulaire/effets des médicaments et des substances chimiques , Mouvement cellulaire/effets des médicaments et des substances chimiques , Endothélium vasculaire/cytologie , Endothélium vasculaire/effets des médicaments et des substances chimiques , Neuropeptides/pharmacologie , Bombésine/pharmacologie , Cellules cultivées , Collagène/pharmacologie , Endostatines , Glucagon/pharmacologie , Humains , Neuropeptide Y/pharmacologie , Fragments peptidiques/pharmacologie , Somatostatine/pharmacologie , Substance P/pharmacologie , Veines ombilicales , Peptide vasoactif intestinal/pharmacologie
12.
Int J Cancer ; 85(6): 850-6, 2000 Mar 15.
Article de Anglais | MEDLINE | ID: mdl-10709107

RÉSUMÉ

Integrin-mediated adhesion of cells to extracellular matrix proteins has been shown to activate various intracellular signaling events. In the present study, we demonstrate that the addition of a monoclonal antibody raised against the beta4 integrin subunit in the culture medium of a clone derived from the colon adenocarcinoma cell line LoVo specifically results in stimulation of cell migration and invasion through reconstituted basement membrane matrices. Moreover, an increase in MMP-2 activity is observed. Conversely, monoclonal anti-alpha6 and anti-beta1 have no effect on MMP-2 expression. The s. c. co-injection of adenocarcinoma cells with antibodies raised against the beta4 integrin subunit to immunosuppressed newborn rats gives rise to tumors displaying altered and disorganized peri-tumoral basement membranes compared with tumors obtained when cells are injected with adenocarcinoma cells alone. Higher metastatic capacity of cells results when they are co-injected with antibodies to the beta4 integrin subunit. Our results suggest that the beta4 subunit of alpha6beta4 integrin, a laminin receptor in colon adenocarcinoma, may be responsible for the specific signals which stimulate cell motility, expression of MMP-2 and tumor invasion.


Sujet(s)
Adénocarcinome/métabolisme , Adénocarcinome/anatomopathologie , Antigènes CD/métabolisme , Tumeurs du côlon/métabolisme , Tumeurs du côlon/anatomopathologie , Matrix metalloproteinase 2/métabolisme , Invasion tumorale , Animaux , Animaux nouveau-nés , Anticorps monoclonaux , Antigènes CD/immunologie , Technique de Southern , Mouvement cellulaire , Humains , Immunohistochimie , Intégrine bêta4 , Laminine/métabolisme , Microscopie électronique , Rats , RT-PCR , Cellules cancéreuses en culture
13.
Am J Pathol ; 156(2): 671-83, 2000 Feb.
Article de Anglais | MEDLINE | ID: mdl-10666396

RÉSUMÉ

Little is known about the functional interactions between digestive neuroendocrine tumor cells and their stromal microenvironment. The focus of our study is whether mesenchymal cells modulate peptide expression, cell proliferation, and invasiveness in digestive neuroendocrine tumor cells. We designed an experimental in vivo and in vitro study using the mouse enteroendocrine cell line STC-1. In vivo, STC-1 cells were injected subcutaneously in 18 immunosuppressed newborn rats. At day 21, all animals presented poorly differentiated neuroendocrine tumors with lung metastases. Subcutaneous tumors were usually limited by a capsule containing basement membrane components and myofibroblasts that presented a low mitotic index. Lung tumors were devoid of capsule and poor in myofibroblasts, and their mitotic index was high. The profile of peptide expression in STC-1 tumors was different from that of cultured STC-1 cells. In vitro, STC-1 cells were cultured with fibroblasts of different origins, including dermis, lung, digestive tract, and liver. Based on their origin, myofibroblasts differentially modulated hormone synthesis, proliferation, spreading, and adhesion of STC-1 cells. In conclusion, our results show that site-specific functional interactions between mesenchymal and neuroendocrine cells may contribute to modulating the behavior of digestive neuroendocrine tumors, depending on their growth site.


Sujet(s)
Tumeurs de l'appareil digestif/physiopathologie , Tumeurs des glandes endocrines/physiopathologie , Tumeurs du système nerveux/physiopathologie , Animaux , Adhérence cellulaire/physiologie , Division cellulaire , Lignée cellulaire/métabolisme , Épithélium/physiopathologie , Fibroblastes/métabolisme , Fibroblastes/physiologie , Hormones/métabolisme , Tumeurs du poumon/anatomopathologie , Mésoderme/physiologie , Souris , Invasion tumorale/anatomopathologie , Peptides/métabolisme , Protéines proto-oncogènes/métabolisme , Protéines proto-oncogènes c-ets , Rats , Rat Wistar , Tumeurs cutanées/anatomopathologie , Facteurs de transcription/métabolisme
14.
Bull Cancer ; 86(2): 154-8, 1999 Feb.
Article de Français | MEDLINE | ID: mdl-10066946

RÉSUMÉ

During the invasive process, tumor cells must move through the extracellular matrix. They have to adhere to the extracellular matrix components, then proteolyse them and migrate on their fragments. This implicates integrins and proteinases, namely metalloproteinases. Numerous experiments which had been performed on various models, namely malignant melanomas proved that integrins have a major role in the transduction of signals from the outside to the inside of the cells, such signals enhancing the expression of the metalloproteinases or, in the contrary, inhibiting it. The modifications of this expression are dependent of extracellular matrix components and may be induced by the linking of specific antibodies to integrins. In some instances, the integrins localized on the tumor cell surface may act as receptors for extracellular matrix proteins and metalloproteinases at once, that may give to tumor cells an higher efficiency in the invasive process. Such mechanisms may result in interesting clinical perspectives for the control of metalloproteinases regulation in pathological processes.


Sujet(s)
Intégrines/physiologie , Metalloendopeptidases/physiologie , Invasion tumorale , Communication cellulaire , Collagenases/physiologie , Activation enzymatique , Fibroblastes/métabolisme , Humains , Matrix metalloproteinase 9 , Mélanome/métabolisme
15.
Differentiation ; 63(3): 141-50, 1998 Jul.
Article de Anglais | MEDLINE | ID: mdl-9697308

RÉSUMÉ

Clone C5 of the human colon adenocarcinoma LoVo cell line was subcutaneously injected with or without exogenous laminin-1 (EHS laminin) into immunosuppressed newborn rats. Cultures were initiated from lung metastases obtained with or without laminin-1 and gave rise to the C5 sublines LM and M4, respectively. The LM subline was mainly composed of spreading cells whereas most C5 and M4 cells remained round and aggregated. The mesenchymal marker vimentin was expressed by very rare C5 and M4 cells (< 1%), and by many LM cells (about 35%). On the opposite, the epithelial markers villin and dipeptidylpeptidase IV were well expressed by C5 cells but not by LM cells. In in vitro migration and invasion assays, LM cells migrated and invaded basement membrane extract twice as much as the parental C5 clone and the M4 subline, probably in association with vimentin-expressing cells, because invasion of basement membrane extract Matrigel by LM cells gave rise to 100% vimentin-positive cells (sublines LM 22, LM 23 and LM 24). When subcutaneously injected, C5 cells induced tumors limited by an interrupted but well organized basement membrane, whereas LM cells induced tumor masses, occasionally limited by a very irregular basement membrane, as observed when C5 cells were injected with laminin-1. Gelatin zymographic analysis clearly showed an increased expression of matrix metalloproteinase-2 by LM cells. Our results suggest a specific role of laminin-1 on the in vivo proliferation of highly invasive vimentin-expressing colon carcinoma cells. This proliferation may result from the initial interaction of C5 cells with large amounts of laminin-1, leading to a selection of vimentin-expressing cells during the metastatic cascade.


Sujet(s)
Adénocarcinome/métabolisme , Adénocarcinome/anatomopathologie , Tumeurs du côlon/métabolisme , Tumeurs du côlon/anatomopathologie , Laminine/pharmacologie , Vimentine/biosynthèse , Animaux , Différenciation cellulaire/physiologie , Mouvement cellulaire , Collagenases/métabolisme , Cellules épithéliales/cytologie , Gelatinases/biosynthèse , Humains , Matrix metalloproteinase 2 , Matrix metalloproteinase 9 , Metalloendopeptidases/biosynthèse , Invasion tumorale , Transplantation tumorale , Phénotype , Rats , Transplantation hétérologue
16.
J Clin Apher ; 13(2): 47-55, 1998.
Article de Anglais | MEDLINE | ID: mdl-9704605

RÉSUMÉ

The purpose of this study was to evaluate the new AMICUS (Baxter-Fenwal Division) cell separator in terms of donor safety, efficiency, and quality of the product obtained. One hundred eighty-three single-donor plateletpheresis procedures were performed, using a collection of 4-4.5 x 10(11) platelets as endpoint. During the first part of the study, the mean volume processed was 3,225 ml and the mean procedure duration 69.5 min. During the second part, after a software change, the mean volume and mean procedure time were 3,071 ml and 68.3 min, respectively. According to local policy, every collection bag was separated into two therapeutic units each containing a mean of 1.87 (1.83) x 10(11) platelets. The white blood cell (WBC) contamination per therapeutic unit was less than 5 x 10(6) in 91% of phereses performed in part one of the study and in 98% of phereses performed in part two. During the recommended 5 days storage, sequential in vitro analyses were performed in 27 units, showing limited platelet activation according to CD62 expression and morphological changes on electron microscopy (EM). Furthermore, there was a correlation between CD62 expression and the degree of WBC contamination (P = 0.03). In conclusion, platelet collection with the new Amicus allows for high platelet yields of adequate quality as judged by WBC content, CD62 expression, and electron microscopic morphological changes.


Sujet(s)
Thrombocytaphérèse/instrumentation , Humains , Numération des leucocytes , Sélectine P/analyse , Transfusion de plaquettes
18.
J Bacteriol ; 178(20): 6049-55, 1996 Oct.
Article de Anglais | MEDLINE | ID: mdl-8830705

RÉSUMÉ

The natural biotic capacity of soils to degrade gamma-hexachlorocyclohexane (gamma-HCH, lindane) was estimated using an enrichment technique based on the ability of soil bacteria to develop on synthetic media and degrade the xenobiotic compound, used as the sole source of carbon and energy. Bacterial inocula from relatively highly contaminated soils (from wood treatment factories) were found to promote efficiently the degradation of gamma-HCH, which subsequently permitted isolation of a competent gamma-HCH-degrading microorganism. The decrease of gamma-HCH concurrently with the release of chloride ions and the production of CO2 demonstrated the complete mineralization of gamma-HCH mediated by the isolate. This was confirmed by gas chromatography-mass spectrometry analyses showing that degradation subproducts of gamma-HCH included an unidentified tetrachlorinated compound and subsequently 1,2,4-trichlorobenzene and 2,5-dichlorophenol. The two linA- and linB-like genes coding, respectively, for a gamma-HCH dehydrochlorinase and a dehalogenase were characterized by using a PCR strategy based on sequence homologies with previously published sequences from Sphingomonas paucimobilis UT26. Nucleotide sequence analysis of the linA-like region revealed the presence of a 472-bp open reading frame exhibiting high homology with the linA gene from S. paucimobilis, while a preliminary study also indicated strong homology among the two linB genes. All enzymes involved in the gamma-HCH degradative pathway appear to be extracellular and encoded by genes located on the chromosome, although numerous cryptic plasmids have been detected.


Sujet(s)
Bactéries/métabolisme , Lindane/métabolisme , Lyases/génétique , Microbiologie du sol , Xénobiotique/métabolisme , Séquence d'acides aminés , Bactéries/enzymologie , Bactéries/génétique , Protéines bactériennes/génétique , Séquence nucléotidique , Dépollution biologique de l'environnement , Clonage moléculaire , Hydrolases/génétique , Industrie , Données de séquences moléculaires , Cartographie de restriction , Analyse de séquence d'ADN , Similitude de séquences d'acides aminés , Polluants du sol
19.
Invasion Metastasis ; 15(3-4): 103-15, 1995.
Article de Anglais | MEDLINE | ID: mdl-8621266

RÉSUMÉ

Malignant transformation is associated with alterations in both cell-cell and cell-matrix interactions. The E2 and C5 clones, derived from the human colon adenocarcinoma LoVo cell line, show, respectively, low and high metastatic capacity as experimental xenografts in vivo. In this study, we have assessed the adhesion and spreading of E2 and C5 cells on basement membrane laminin, expression of the laminin receptor integrins alpha 6 beta 1 and alpha 6 beta 4 and expression of gelatinolytic and plasminogen-dependent activities. On days 5 and 7 after subcutaneous grafting to immunosuppressed newborn rats, well-differentiated E2 tumors displayed a polarized expression of these integrin subunits, with the exception of the beta 1 subunit which remained pericellular. In contrast, C5 tumors were unorganized and the three integrin subunits remained nonpolarized and pericellular. Flow cytometry results showed that the expression of alpha 6 beta 1 and alpha 1 beta 4 integrins was weaker in the highly metastatic C5 clone than in the E2 clone whereas laminin expression was not significantly different. Under-expression and pericellular localization of these integrin receptors in C5 cells as compared to E2 cells may explain the difference in their binding and spreading capacity on laminin, organization of peritumoral basement membrane and maintenance of a differentiated phenotype. Whereas similar levels of gelatinolytic and plasminogen activator activities have been detected in the culture supernatant of the two clones, histozymograms showed that plasminogen-dependent caseinolysis appeared earlier in sections of C5 and parental tumors than in those of E2 xenografts. These results suggest that enhanced aggressiveness of C5 tumors in vivo may be linked to both an impairment of basement membrane setting due to integrin underexpression and distribution and of proteolytic activities modulated by tumor/host interactions.


Sujet(s)
Adénocarcinome/métabolisme , Tumeurs du côlon/métabolisme , Intégrines/biosynthèse , Adénocarcinome/anatomopathologie , Animaux , Membrane basale/métabolisme , Adhérence cellulaire , Mouvement cellulaire , Tumeurs du côlon/anatomopathologie , Électrophorèse sur gel de polyacrylamide , Femelle , Fibrinolysine/métabolisme , Technique d'immunofluorescence , Humains , Sujet immunodéprimé , Immunohistochimie , Laminine/métabolisme , Métastase tumorale , Transplantation tumorale , Grossesse , Rats , Cellules cancéreuses en culture
20.
Vet Res ; 25(5): 478-88, 1994.
Article de Anglais | MEDLINE | ID: mdl-7951350

RÉSUMÉ

Visna-maedi virus is a lentivirus that causes a chronic disease in sheep affecting, among other organs, the lungs. Interstitial pneumonitis is similar to that in man associated with the infection by the human immunodeficiency virus type-1. We have compared the pathological features of lungs of sheep naturally infected with visna-maedi virus with the results obtained from bronchoalveolar lavage and virus isolation. Semi-quantitative grading of the lesions was performed on 147 sheep lungs obtained from the slaughterhouse. Seventy-seven were macroscopically and histologically normal, 39 had typical lesions of interstitial lung disease (maedi), and 13 had minor lesions of the same type. Eighteen of the affected lungs were heavily infested with parasites. Of these parasite-infected lungs, 9 showed typical maedi lesions and 4 showed minor lesions; parasite infection had no obvious effect on the development of maedi. In keeping with pathological findings, bronchoalveolar lavage disclosed an alveolitis process in the maedi lungs with increased macrophage, lymphocyte and neutrophil numbers. Cytopathic virus was detected from alveolar macrophage coculture with fibroblasts more often from maedi lungs (10/12) than from normal lungs (9/39). Electron microscopy of bronchoalveolar lavage cocultures revealed typical lentiviral particles. Animals with minor lesions may be at an early stage of the disease.


Sujet(s)
Poumon/anatomopathologie , Pneumonie interstitielle progressive du mouton/anatomopathologie , Animaux , Liquide de lavage bronchoalvéolaire/cytologie , Liquide de lavage bronchoalvéolaire/microbiologie , Numération cellulaire/médecine vétérinaire , Effet cytopathogène viral , Cellules géantes , Ovis , Virus maedi-visna/isolement et purification
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