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1.
J Biophotonics ; 17(6): e202300513, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38531615

RÉSUMÉ

Cystic echinococcosis (CE) is a global health concern caused by cestodes, posing diagnostic challenges due to nonspecific symptoms and inconclusive radiographic results. Diagnosis relies on histopathological evaluation of affected tissue, demanding comprehensive tools. In this retrospective case study, Fourier transform infrared microscopy was explored for detecting and identifying CE through biochemical changes in human tissue sections. Tissue samples from 11 confirmed CE patients were analyzed. Archived FFPE blocks were cut and stained, and then CE-positive unstained sections were examined using Fourier transform infrared microscopy post-deparaffinization. Results revealed the method's ability to distinguish echinococcus elements from human tissue, irrespective of organ type. This research showcases the potential of mid-infrared microscopy as a valuable diagnostic tool for CE, offering promise in enhancing diagnostic precision in the face of the disease's complexities.


Sujet(s)
Échinococcose , Humains , Échinococcose/imagerie diagnostique , Échinococcose/anatomopathologie , Spectroscopie infrarouge à transformée de Fourier , Microscopie , Études rétrospectives , Femelle
2.
Adv Parasitol ; 109: 111-130, 2020.
Article de Anglais | MEDLINE | ID: mdl-32381193

RÉSUMÉ

Toxocara canis and T. cati are among the most widely distributed helminthic species in the world with a high zoonotic impact. Millions of people are infecteda and hundreds of thousands are suffering from toxocarosis, a disease encompassing four different entities: larva migrans visceralis (VLM) syndrome, ocular larva migrans (OLM) syndrome, covert toxocarosis (covT), common toxocarosis (comT) and neurotoxocarosis (NT). Toxocara infections in humans may remain clinically inapparent but may also induce severe diseases. This contribution gives a synoptic overview of the most important historical, clinical, diagnostic and therapeutical aspects of toxocarosis in humans.


Sujet(s)
Toxocarose/parasitologie , Animaux , Humains , Larva migrans/diagnostic , Larva migrans/parasitologie , Larva migrans/thérapie , Toxocara , Toxocara canis , Toxocarose/diagnostic , Toxocarose/thérapie
3.
Schweiz Arch Tierheilkd ; 160(11): 659-664, 2018 Nov.
Article de Anglais | MEDLINE | ID: mdl-30379133

RÉSUMÉ

INTRODUCTION: This case report describes a 13-year-old cob-cross gelding presented for evaluation of recent onset hindlimb ataxia. The gelding had undergone general anaesthesia and tenoscopy of the right hindlimb digital flexor tendon sheath at a nearby clinic three months earlier and had appeared normal at routine post-operative assessments until the sudden onset of neurological deficits. Spinal trauma was suspected initially but radiography and scintigraphy were unremarkable. Due to the severity and progressive nature of the clinical signs the -gelding was subjected to euthanasia. Post mortem examinations (computed tomography, dissection and histopathology) revealed spinal cord compression caused by a single extradural hydatid cyst (Echinococcus equinus), confirmed with PCR, at the level of the 15th thoracic vertebra. This is the first report of a spinal hydatid cyst causing hindlimb ataxia and should therefore be considered a potential differential diagnosis for ataxia in the equine patient.


INTRODUCTION: Ce rapport décrit le cas d'un hongre croisé cob de 13 ans présenté pour l'évaluation d'une ataxie des membres postérieurs d'apparition récente. Le hongre avait subi une anesthésie générale et une ténoscopie de la gaine du tendon du fléchisseur digital du membre postérieur droit dans une clinique voisine trois mois auparavant et avait semblé normal lors des évaluations postopératoires de routine jusqu'à l'apparition soudaine de déficits neurologiques. Un traumatisme rachidien était suspecté au départ, mais la radiographie et la scintigraphie étaient sans particularité. En raison de la gravité et de la nature progressive des signes cliniques, le hongre a été euthanasié. Les examens post mortem (tomodensitométrie, dissection et histopathologie) ont révélé une compression de la moelle épinière provoquée par un unique kyste hydatique extradural (Echinococcus equinus), confirmé par PCR, au niveau de la 15e vertèbre thoracique. Il s'agit du premier cas rapporté d'un kyste hydatique au niveau de la colonne vertébrale causant une ataxie des membres postérieurs et doit donc être considéré comme un diagnostic différentiel potentiel de l'ataxie chez le patient équin.


Sujet(s)
Ataxie/médecine vétérinaire , Échinococcose/médecine vétérinaire , Echinococcus/isolement et purification , Membre pelvien/physiopathologie , Maladies des chevaux/diagnostic , Syndrome de compression médullaire/médecine vétérinaire , Animaux , Ataxie/parasitologie , Ataxie/physiopathologie , Échinococcose/diagnostic , Échinococcose/parasitologie , Euthanasie animale , Maladies des chevaux/parasitologie , Maladies des chevaux/physiopathologie , Equus caballus , Mâle , Syndrome de compression médullaire/diagnostic , Syndrome de compression médullaire/parasitologie
4.
Mol Hum Reprod ; 23(8): 535-548, 2017 08 01.
Article de Anglais | MEDLINE | ID: mdl-28586423

RÉSUMÉ

STUDY QUESTION: How does the human oocyte transcriptome change with age and ovarian reserve? SUMMARY ANSWER: Specific sets of human oocyte messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs) are affected independently by age and ovarian reserve. WHAT IS KNOWN ALREADY: Although it is well established that the ovarian reserve diminishes with increasing age, and that a woman's age is correlated with lower oocyte quality, the interplay of a diminished reserve and age on oocyte developmental competence is not clear. After maturation, oocytes are mostly transcriptionally quiescent, and developmental competence prior to embryonic genome activationrelies on maternal RNA and proteins. STUDY DESIGN, SIZE, DURATION: A total of 36 vitrified/warmed MII oocytes from 30 women undergoing oocyte donation were included in this study, processed and analyzed individually. PARTICIPANTS/MATERIALS, SETTING, METHODS: Total RNA from each oocyte was independently isolated, amplified, labeled, and hybridized on HTA 2.0 arrays (Affymetrix). Data were analyzed using TAC software, in four groups, each including nine oocytes, according to the woman's age and antral follicular count (AFC) (mean ± SD): Young with High AFC (YH; age 21 ± 1 years and 24 ± 3 follicles); Old with High AFC (OH; age 32 ± 2 years and 29 ± 7 follicles); Young with Low AFC (YL; age 24 ± 2 years and 8 ± 2 follicles); Old with Low AFC (OL; age 34 ± 1 years and 7 ± 1 follicles). qPCR was performed to validate arrays. MAIN RESULTS AND THE ROLE OF CHANCE: We identified a set of 30 differentially expressed mRNAs when comparing oocytes from women with different ages and AFC. In addition, 168 non-coding RNAs (ncRNAs) were differentially expressed in relation to age and/or AFC. Few mRNAs have been identified as differentially expressed transcripts, and among ncRNAs, a set of Piwi-interacting RNAs clusters (piRNAs-c) and precursor microRNAs (pre-miRNAs) were identified as increased in high AFC and old groups, respectively. Our results indicate that age and ovarian reserve are associated with specific ncRNA profiles, suggesting that oocyte quality might be mediated by ncRNA pathways. LARGE SCALE DATA: Data can be found via GEO accession number GSE87201. LIMITATIONS, REASONS FOR CAUTION: The oldest woman included in the study was 35 years old, thus our results cannot readily be extrapolated to women older than 35 or infertile women. WIDER IMPLICATIONS OF THE FINDINGS: We show, for the first time, that several non-coding RNAs, usually regulating DNA transcription, are differentially expressed in relation to age and/or ovarian reserve. Interestingly, the mRNA transcriptome of in vivo matured oocytes remains remarkably stable across ages and ovarian reserve, suggesting the possibility that changes in the non-coding transcriptome might regulate some post-transcriptional/translational mechanisms which might, in turn, affect oocyte developmental competence. STUDY FUNDING AND COMPETING INTEREST(S): This work was supported by intramural funding of Clinica EUGIN and by the Secretary for Universities and Research of the Ministry of Economy and Knowledge of the Government of Catalonia. J.H. and A.S. are employees of Affymetrix, otherwise there are no competing interests.


Sujet(s)
Vieillissement/physiologie , Ovocytes/métabolisme , Follicule ovarique/cytologie , Transcriptome , Adulte , Séparation cellulaire , Femelle , Humains , Ovogenèse , Contrôle de qualité , ARN/métabolisme , Jeune adulte
5.
Biotech Histochem ; 89(7): 518-28, 2014 Oct.
Article de Anglais | MEDLINE | ID: mdl-24799092

RÉSUMÉ

Unfixed tissue specimens most frequently are stored for long term research uses at either -80° C or in vapor phase liquid nitrogen (VPLN). There is little information concerning the effects such long term storage on tissue RNA or protein available for extraction. Aliquots of 49 specimens were stored for 5-12 years at -80° C or in VPLN. Twelve additional paired specimens were stored for 1 year under identical conditions. RNA was isolated from all tissues and assessed for RNA yield, total RNA integrity and mRNA integrity. Protein stability was analyzed by surface-enhanced or matrix-assisted laser desorption ionization time of flight mass spectrometry (SELDI-TOF-MS, MALDI-TOF-MS) and nano-liquid chromatography electrospray ionization tandem mass spectrometry (nLC-ESI-MS/MS). RNA yield and total RNA integrity showed significantly better results for -80° C storage compared to VPLN storage; the transcripts that were preferentially degraded during VPLN storage were these involved in antigen presentation and processing. No consistent differences were found in the SELDI-TOF-MS, MALDI-TOF-MS or nLC-ESI-MS/MS analyses of specimens stored for more than 8 years at -80° C compared to those stored in VPLN. Long term storage of human research tissues at -80° C provides at least the same quality of RNA and protein as storage in VPLN.


Sujet(s)
Congélation , Protéines/composition chimique , ARN/composition chimique , Conservation de tissu/méthodes , Basse température , Analyse de profil d'expression de gènes , Humains , Analyse sur microréseau , Tumeurs/anatomopathologie , Protéomique/méthodes , ARN messager/composition chimique , Spectrométrie de masse MALDI
6.
Vector Borne Zoonotic Dis ; 13(11): 798-803, 2013 Nov.
Article de Anglais | MEDLINE | ID: mdl-24107202

RÉSUMÉ

Despite emerging risks for the spread of zoonotic diseases, data on human exposure to Echinococcus multilocularis and Toxocara spp., the causative parasites of the two most important helminthozoonoses in Central Europe, are limited. To investigate risk factors and exposure, we conducted a nationwide, cross-sectional serological study in 1046 healthy individuals, of which 425 were soldiers and 621 were civilians. Serum samples and information on possible risk factors for exposure, including previous foreign military assignments, residential area, animal contact, and regular outdoor activities, were obtained. Immunoglobulin G antibodies against Echinococcus multilocularis and Toxocara spp. were examined with an enzyme-linked immunosorbent assay (ELISA). Samples reactive in the ELISA for antibodies against Echinococcus multilocularis were considered positive only after confirmation by western blot. Overall, 66 (6.3%) individuals tested positive in the serologic screening for Toxocara spp. Occupational animal contact was the only risk factor significantly associated with a higher risk for being seropositive. None of the individuals were positive for antibodies against Echinococcus multilocularis. In conclusion, the present study demonstrates that exposure to Toxocara spp. is widespread in Austria and occupational animal contact is a risk factor for seropositivity.


Sujet(s)
Anticorps antihelminthe/sang , Échinococcose/épidémiologie , Echinococcus multilocularis/immunologie , Toxocara/immunologie , Toxocarose/épidémiologie , Adolescent , Adulte , Animaux , Autriche/épidémiologie , Études transversales , Echinococcus multilocularis/isolement et purification , Test ELISA , Femelle , Humains , Mâle , Adulte d'âge moyen , Personnel militaire , Facteurs de risque , Études séroépidémiologiques , Toxocara/isolement et purification , Toxocara canis/immunologie , Toxocara canis/isolement et purification , Voyage , Jeune adulte , Zoonoses
7.
J Helminthol ; 87(3): 257-70, 2013 Sep.
Article de Anglais | MEDLINE | ID: mdl-23046708

RÉSUMÉ

Cerebral involvement in parasitoses is an important clinical manifestation of most of the human parasitoses. Parasites that have been described to affect the central nervous system (CNS), either as the dominant or as a collateral feature, include cestodes (Taenia solium (neurocysticerciasis), Echinococcus granulosus (cerebral cystic echinococcosis), E. multilocularis (cerebral alveolar echinococcosis), Spirometra mansoni (neurosparganosis)), nematodes (Toxocara canis and T. cati (neurotoxocariasis), Trichinella spiralis (neurotrichinelliasis), Angiostrongylus cantonensis and A. costaricensis (neuroangiostrongyliasis), Gnathostoma spinigerum (gnathostomiasis)), trematodes (Schistosoma mansoni (cerebral bilharziosis), Paragonimus westermani (neuroparagonimiasis)), or protozoa (Toxoplasma gondii (neurotoxoplasmosis), Acanthamoeba spp. or Balamuthia mandrillaris (granulomatous amoebic encephalitis), Naegleria (primary amoebic meningo-encephalitis), Entamoeba histolytica (brain abscess), Plasmodium falciparum (cerebral malaria), Trypanosoma brucei gambiense/rhodesiense (sleeping sickness) or Trypanosoma cruzi (cerebral Chagas disease)). Adults or larvae of helminths or protozoa enter the CNS and cause meningitis, encephalitis, ventriculitis, myelitis, ischaemic stroke, bleeding, venous thrombosis or cerebral abscess, clinically manifesting as headache, epilepsy, weakness, cognitive decline, impaired consciousness, confusion, coma or focal neurological deficits. Diagnosis of cerebral parasitoses is dependent on the causative agent. Available diagnostic tools include clinical presentation, blood tests (eosinophilia, plasmodia in blood smear, antibodies against the parasite), cerebrospinal fluid (CSF) investigations, imaging findings and occasionally cerebral biopsy. Treatment relies on drugs and sometimes surgery. Outcome of cerebral parasitoses is highly variable, depending on the effect of drugs, whether they are self-limiting (e.g. Angiostrongylus costaricensis) or whether they remain undetected or asymptomatic, like 25% of neurocysticerciasis cases.


Sujet(s)
Infections parasitaires du système nerveux central/épidémiologie , Infections parasitaires du système nerveux central/parasitologie , Parasites/classification , Parasites/isolement et purification , Animaux , Antiparasitaires/usage thérapeutique , Infections parasitaires du système nerveux central/diagnostic , Infections parasitaires du système nerveux central/anatomopathologie , Techniques de laboratoire clinique/méthodes , Médecine clinique/méthodes , Humains
8.
Clin Microbiol Infect ; 19(6): 572-7, 2013 Jun.
Article de Anglais | MEDLINE | ID: mdl-22764887

RÉSUMÉ

Leishmaniasis is a rare disease in Central Europe and is diagnosed almost exclusively in travellers or migrants coming from tropical or subtropical countries. We conducted an explorative cross-sectional serological study, using a commercial ELISA, in 1048 healthy Austrian individuals to assess the distribution of specific antibodies against Leishmania spp. in humans in Austria. Overall, 47 individuals (4.5%) tested positive, and an additional 32 (3.1%) showed borderline results. After 12 months, sera from 42 of the 79 individuals who had initially tested seropositive/borderline were tested by ELISA a second time: 18 were persistently positive, nine were borderline. Those whose sera were persistently positive/borderline were then screened for potential carrier status using a commercial oligochromatographic PCR test to detect parasite DNA. Four samples were PCR positive and were subjected to a second PCR allowing parasite identification after DNA sequencing: two samples were identified as Leishmania donovani/infantum complex and Leishmania (Viannia) guyanensis, respectively. Epidemiological information was obtained with a questionnaire: no correlation was found for the number of holiday trips within the previous 6 months, but a significant risk of exposure to Leishmania spp. was found for travel to the New World, particularly to the Caribbean. Our data demonstrate that Leishmania spp. seroprevalence in non-endemic countries has been considerably underestimated.


Sujet(s)
Leishmania , Leishmaniose/épidémiologie , Adolescent , Adulte , Anticorps antiprotozoaires/sang , Anticorps antiprotozoaires/immunologie , Autriche/épidémiologie , Études transversales , Espaceur de l'ADN ribosomique/génétique , Test ELISA , Femelle , Études de suivi , Humains , Leishmania/génétique , Leishmania/immunologie , Leishmaniose/immunologie , Mâle , Adulte d'âge moyen , Facteurs de risque , Études séroépidémiologiques , Jeune adulte
9.
Z Gastroenterol ; 47(10): 1059-61, 2009 Oct.
Article de Allemand | MEDLINE | ID: mdl-19809956

RÉSUMÉ

Anisakiasis is caused by a fish parasite of the Nematode family. This kind of rare helminthozoonosis can mainly be found in countries where consumption of raw fish is traditionally high like Japan, the Netherlands, Pacific Islands, South Europe, Scandinavia, USA, and Canada. Man is the wrong hoste. Clinical manifestation depends on the localisation of penetration in the GI tract. In Japan, predominantly the stomach is affected in 97 % of cases, probably due to hypo- and achlorhydria; whereas mainly intestinal anisakiasis occurs in Europa. We report on a 67-year-old male patient with a gastric infestation of anisakiasis. The patient was on proton pump inhibitor which migh have caused the localisation of the infestation. The anisakis was an accidental endoscopic finding in a patient for control of an H. p.-positive gastric ulcer. Otherwise the patient was free of pain. The helminth (larva III) was endoscopically extracted. Thereafter, the patient remained in good health. Anisakis serology as well as repeated differential blood counts were without finding. The uneventful medical history and the normal blood findings indicate that our patient had a very early stage of infestation of anisakiasis. The patient reported no stay outside of Austria within the last years. However, he consumed on a regular basis "rolled pickled herring" produced by a well-known Viennese company for canned fish. This is the first documented case of this rare helminthozoonosis acquired in Austria.


Sujet(s)
Anisakiase/diagnostic , Anisakiase/chirurgie , Sujet âgé , Autriche , Humains , Maladies rares , Résultat thérapeutique
11.
Cytogenet Genome Res ; 123(1-4): 278-82, 2008.
Article de Anglais | MEDLINE | ID: mdl-19287165

RÉSUMÉ

DNA copy number variation (CNV) was recently discovered as a significant part of human genetic variation. This variation affects genes as well as intergenic regions. Herein, current insight into the effects of CNV on gene expression is summarized. The consequences of intergenic CNVs are poorly understood. For CNV affecting genes, a dosage compensation mechanism seems to be applied on a subset of genes only, while others show augmented expression caused by increasing copy number. For the latter case, extensive literature reports a positive correlation between gene copy number and gene expression. Recent advances in techniques for genome-wide measurements of CNV and gene expression are described. These advances will soon allow the generation of comprehensive maps of these two phenomena, which will contribute to our understanding of the mechanisms underlying how CNV affects gene expression.


Sujet(s)
Dosage génique/génétique , Régulation de l'expression des gènes/génétique , Génome humain/génétique , Animaux , Humains , ARN non traduit/génétique
12.
Acta Trop ; 104(2-3): 122-32, 2007.
Article de Anglais | MEDLINE | ID: mdl-17915186

RÉSUMÉ

Anthelmintic activity of benzimidazole carbamate anthelmintics is low against dormant Toxocara canis larvae during late infections in paratenic hosts. The present study was conducted to examine the efficacy of pure fenbendazole, or drug incorporated into sterically stabilized liposomes (SL-FBZ) administered to T. canis-infected mice alone and after its co-administration with the immunomodulator (1-->3)-beta-D-glucan against larvae localized in muscles and brains. Therapy with either drug forms (in total 250 mg/kg in 10 doses) commenced on day 28 post-infection (p.i.) and the efficacy of treatment, examined on day 30 after the last dose of drug, was the highest in groups of mice treated with SL-FBZ in combination with glucan (89.5+/-5.8% in the muscles, 66.1+/-8.1% in brains). During 56 days of follow-up after termination of therapy, serum levels of anti-TES IgG antibodies, circulating IgG-TES immune complexes (CIC) as well as IgG antibodies to the most immunogenic part of recombinant myosin antigen of T. canis larvae were investigated. In contrast to anti-TES IgG antibodies, levels of CIC and anti-myosin antibodies were in the linear correlation with the efficacy of treatments beginning from day 38 post-therapy. We also showed that the serum levels of CIC as well as anti-myosin IgG antibodies seem to be the suitable serological markers for the monitoring of progress in larval destruction and TES resorption from the tissues.


Sujet(s)
Fenbendazole/usage thérapeutique , Glucanes/usage thérapeutique , Toxocara canis/immunologie , Toxocarose/traitement médicamenteux , Animaux , Anticorps antihelminthe/sang , Technique de Western , Encéphale/effets des médicaments et des substances chimiques , Encéphale/parasitologie , Association de médicaments , Électrophorèse sur gel de polyacrylamide , Test ELISA , Fenbendazole/composition chimique , Glucanes/composition chimique , Protéines d'helminthes/immunologie , Immunoglobuline G/sang , Facteurs immunologiques/composition chimique , Facteurs immunologiques/usage thérapeutique , Larve/effets des médicaments et des substances chimiques , Larve/immunologie , Liposomes/composition chimique , Mâle , Souris , Souris de lignée C57BL , Muscles/effets des médicaments et des substances chimiques , Muscles/parasitologie , Myosines/immunologie , Toxocarose/immunologie , Toxocarose/parasitologie , Résultat thérapeutique
13.
Phys Rev Lett ; 92(18): 187004, 2004 May 07.
Article de Anglais | MEDLINE | ID: mdl-15169527

RÉSUMÉ

We investigate the electronic structure and the hole content in the copper-oxygen planes of Hg-based high T(c) cuprates for one to four CuO2 layers and hydrostatic pressures up to 15 GPa. We find that with the pressure-induced additional number of holes of the order of 0.05e the density of states at the Fermi level changes by approximately a factor of 2. At the same time, the saddle point is moved to the Fermi level accompanied by an enhanced k(z) dispersion. This finding explains the pressure behavior of T(c) and leads to the conclusion that the applicability of the van Hove scenario is restricted. By comparison with experiment, we estimate the coupling constant to be of the order of 1, ruling out the weak coupling limit.

14.
Parasitology ; 128(Pt 5): 569-75, 2004 May.
Article de Anglais | MEDLINE | ID: mdl-15180325

RÉSUMÉ

Genetic analyses of Echinococcus granulosus isolates from different intermediate host species have demonstrated substantial levels of variation for some genotype (strain) clusters. To determine the range of genetic variability within and between genotypes we amplified and cloned partial cox1 and nadh1 genes from 16 isolates of E. granulosus from 4 continents. Furthermore, we sequenced different clones from a PCR product to analyse the intra-individual genetic variance. The findings showed a moderate degree of variance within single isolates and a significant degree of variance between the cluster of genotypes G1-G3 (sheep, Tasmanian sheep and buffalo strain), genotypes G4 (horse strain) and G5 (cattle strain) and the cluster of the genotypes G6 (camel strain) and G7 (pig strain). The variance of up to 2.2% within genotypes was relatively low compared with that of 4.3-15.7% among genotypes. The present results indicate that a re-examination of the classification of 5 genotypes of Echinococcus is warranted. Hence, our data highly support a re-evaluation of the taxonomy of the clades G1-G3, G4, G5, G6/7 and G8 (cervid strain) within the genus Echinococcus.


Sujet(s)
ADN mitochondrial/génétique , Echinococcus/génétique , Complexe IV de la chaîne respiratoire/génétique , NADH dehydrogenase/génétique , Animaux , Séquence nucléotidique , Analyse de regroupements , ADN mitochondrial/composition chimique , ADN des protozoaires/composition chimique , ADN des protozoaires/génétique , Echinococcus/classification , Echinococcus/enzymologie , Complexe IV de la chaîne respiratoire/composition chimique , Variation génétique , Humains , Données de séquences moléculaires , NADH dehydrogenase/composition chimique , Phylogenèse , Réaction de polymérisation en chaîne , Pseudogènes , Alignement de séquences , Analyse de séquence d'ADN
15.
Clin Exp Allergy ; 33(1): 22-7, 2003 Jan.
Article de Anglais | MEDLINE | ID: mdl-12534545

RÉSUMÉ

BACKGROUND: Almost no information is available regarding the prevalence of IgE-mediated allergies and the disease-eliciting allergens in tropical Africa. OBJECTIVE: To study IgE-mediated allergies and the allergen profile in allergic patients from Zimbabwe. METHODS: The frequency of sensitization to common environmental allergen sources was determined by skin prick testing in 650 allergic patients from Zimbabwe. Fifty representative sera were analysed for IgE reactivity to 20 respiratory and 20 food allergen extracts by multiallergen extract testing. The IgE reactivity profiles to recombinant pollen and mite allergens were compared between grass pollen- and mite-sensitized patients from Zimbabwe and central Europe. Sera from grass pollen-allergic patients were also analysed for IgE reactivity to nitrocellulose-blotted natural timothy grass and Bermuda grass pollen allergens. RESULTS: IgE-mediated allergies were found to be common in Zimbabwe. Similar to the situation in central Europe, mites and grass pollens represented the most prevalent allergen sources. However, the IgE reactivity profiles determined with single recombinant pollen and mite allergens revealed interesting differences between the European and African patients, which most likely reflect the local allergen exposure. CONCLUSIONS: The striking differences regarding sensitization to grass pollen and mite allergens between African and European patients revealed by recombinant allergen-based testing emphasize the need for component-resolved allergy testing to optimize allergy prevention and therapy in different populations.


Sujet(s)
Allergènes , Exposition environnementale , Hypersensibilité/épidémiologie , Immunoglobuline E/immunologie , Adolescent , Adulte , Animaux , Enfant , Enfant d'âge préscolaire , Dermatophagoides pteronyssinus , Europe/épidémiologie , Femelle , Humains , Hypersensibilité/immunologie , Incidence , Nourrisson , Mâle , Adulte d'âge moyen , Poaceae , Pollen , Protéines recombinantes , Tests cutanés , Zimbabwe/épidémiologie
16.
Biochemistry ; 40(46): 14020-9, 2001 Nov 20.
Article de Anglais | MEDLINE | ID: mdl-11705394

RÉSUMÉ

The pi-helix is a secondary structure with 4.4 amino acids per helical turn. Although it was proposed in 1952, no experimental support for its existence was obtained until the mid-1980s. While short peptides are unlikely to assume a marginally stable secondary structure spontaneously, they might do so in the presence of appropriate structural constraints. In this paper, we describe a peptide that is designed to assume a pi-helical conformation when stabilized by cetyltrimethylammonium bromide (CTAB) micelles and Zn(2+). In the designed peptide, lipophilic amino acids are placed such that it would be amphiphilic in the pi-helical, but not in the alpha-helical, conformation. Also, two His residues are incorporated with i, i + 5 spacing, designed to allow binding of Zn(2+) in a pi-helical but not an alpha-helical conformation. The peptide was found to form moderately stable monolayers at the air-water interface, with a collapse pressure that almost doubled when there was Zn(2+) in the subphase. Also, CTAB micelles induced a marked increase in the helicity of the peptide. In 50% TFE, the peptide had a CD spectrum consistent with an alpha-helical structure. The addition of 1 mM Zn(2+) to this solvent caused a saturable decline in ellipticity to approximately half of its original value. The peptide also bound Zn(2+) when it was bound to CTAB micelles, with Zn(2+) again inducing a decrease in ellipticity. The peptide had slightly greater affinity for Zn(2+) in the presence of the CTAB than in a 50% TFE solution (K(d) = 3.1 x 10(-4) M in CTAB and 2.3 x 10(-4) M in TFE). van't Hoff analysis indicated that thermal denaturation of the peptide in 50% TFE containing 1 mM Zn(2+) was associated with both enthalpic and entropic changes that were greater than those in the absence of Zn(2+). These observations are all consistent with the proposal that the peptide assumed a pi-helical conformation in the presence of Zn(2+) and CTAB micelles, and has allowed the stability of this rare conformation to be assessed.


Sujet(s)
Peptides/synthèse chimique , Peptides/métabolisme , Zinc/métabolisme , Séquence d'acides aminés , Substitution d'acide aminé , Apolipoprotéines E/synthèse chimique , Apolipoprotéines E/métabolisme , Bromure de cétrimonium , Composés de cétrimonium/pharmacologie , Dichroïsme circulaire , Stabilité enzymatique , Humains , Données de séquences moléculaires , Pression , Liaison aux protéines/effets des médicaments et des substances chimiques , Ingénierie des protéines , Structure secondaire des protéines/effets des médicaments et des substances chimiques , Propriétés de surface , Thermodynamique
17.
Bone Marrow Transplant ; 28(5): 519-21, 2001 Sep.
Article de Anglais | MEDLINE | ID: mdl-11593327

RÉSUMÉ

A girl with myelodysplastic syndrome (RAEB-T) received HLA-identical bone marrow from her younger brother after myeloablative treatment with busulfan and cyclophosphamide. After bone marrow transplantation, fever, exanthema, pruritus, and a pulmonary infiltrate were treated symptomatically. Bacterial cultures remained negative. Leukocyte engraftment began on day 10, and all blood cell populations proved to be of donor origin on FISH analysis. Increasing IgE levels (21 000 U/ml) on day 14 after BMT, positive RAST, specific IgG-antibodies, and missing Toxocara (T.) canis antigens in the recipient indicated donor-derived seroconversion. Before BMT, the recipient had been negative for T. canis in routine parasitological screening, and the donor proved to be positive for T. canis antibody by ELISA. This report suggests that the transfer of IgE immunity in the absence of detectable antigens may be responsible for IgE-mediated symptoms consistent with toxocara infection and confirms the need for parasite screening in donor medical examinations.


Sujet(s)
Transplantation de moelle osseuse , Immunoglobuline E/biosynthèse , Toxocara canis/immunologie , Toxocarose/immunologie , Transfert adoptif/méthodes , Animaux , Anticorps antihelminthe/biosynthèse , Transplantation de moelle osseuse/effets indésirables , Enfant , Enfant d'âge préscolaire , Femelle , Humains , Mâle , Syndromes myélodysplasiques/thérapie , Toxocara canis/isolement et purification , Transplantation homologue
18.
J Ocul Pharmacol Ther ; 17(3): 287-94, 2001 Jun.
Article de Anglais | MEDLINE | ID: mdl-11436948

RÉSUMÉ

The purpose of this study was to evaluate the efficacy of combined albendazole and steroid treatment for uveitis caused by Toxocara canis in immunocompetent patients. Five patients (7 eyes) with ocular larva migrans syndrome (OLM) were used in this study. Toxocariasis was suspected based on clinical manifestations and confirmed by anti-toxocara IgG and Western blot analysis. Systemic albendazole (adults: 800 mg b.i.d.; children: 400 mg b.i.d.) was given in conjunction with steroids. Visual acuity before and after therapy, inflammatory response, side effects and toxicity were evaluated. Treatment resulted in an improved visual acuity in all patients. Mean initial Snellen visual acuity was 20/40, and mean final acuity was 20/20. There were no recurrences of uveitis throughout the observation period (average: 13.8 months; range: 3 days to 24 months). These findings suggest that albendazole, in combination with systemic steroids, is a useful regimen to treat ocular larva migrans syndrome.


Sujet(s)
Antiprotozoaires/usage thérapeutique , Parasitoses oculaires/traitement médicamenteux , Glucocorticoïdes/usage thérapeutique , Toxocarose/traitement médicamenteux , Uvéite postérieure/traitement médicamenteux , Adolescent , Adulte , Sujet âgé , Albendazole/usage thérapeutique , Animaux , Anticorps antihelminthe/analyse , Technique de Western , Enfant , Association de médicaments , Parasitoses oculaires/diagnostic , Parasitoses oculaires/parasitologie , Femelle , Humains , Immunoglobuline G/analyse , Mâle , Adulte d'âge moyen , Prednisolone/usage thérapeutique , Toxocara/immunologie , Toxocarose/diagnostic , Toxocarose/parasitologie , Résultat thérapeutique , Uvéite postérieure/diagnostic , Uvéite postérieure/parasitologie , Acuité visuelle
20.
Parasitol Res ; 87(5): 383-9, 2001 May.
Article de Anglais | MEDLINE | ID: mdl-11403381

RÉSUMÉ

Myosins from nematode parasites elicit strong humoral and cellular immune responses and have been investigated as vaccine candidates. In this study we cloned and sequenced a cDNA coding for myosin heavy chain from Toxocara canis, a nematode parasite of canids which may also infect humans and cause various unspecific symptoms. To determine the major antigenic regions the myosin heavy chain was systematically dissected into ten overlapping recombinant fusion polypeptides which were purified by metal chelate chromatography. Single fragments were then tested for their IgG reactivity in sera from toxocarosis patients and healthy probands. Two regions, one region at the mid to carboxy-terminal end of the head domain and one region in the rod domain, were identified as major antigens, which in combination were positive with 86% of the sera. The other domains were less reactive. This shows that the patients' IgG reactivity was not directed evenly against all parts of the molecule, but was rather clustered in few regions.


Sujet(s)
Antigènes d'helminthe/immunologie , Chaînes lourdes de myosine/immunologie , Protéines de fusion recombinantes/immunologie , Toxocara canis/immunologie , Séquence d'acides aminés , Animaux , Clonage moléculaire , Amorces ADN/composition chimique , ADN complémentaire/analyse , ADN des helminthes/analyse , Humains , Immunotransfert , Immunoglobuline G/immunologie , Souris , Données de séquences moléculaires , Analyse de séquence d'ADN , Toxocarose/sang
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