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1.
Ecol Appl ; 30(3): e02058, 2020 04.
Article de Anglais | MEDLINE | ID: mdl-31838775

RÉSUMÉ

Most spatial conservation planning for wide-ranging or migratory species is constrained by poor knowledge of species' spatiotemporal dynamics and is only based on static species' ranges. However, species have substantial variation in abundance across their range and migratory species have important spatiotemporal population dynamics. With growing ecological data and advancing analytics, both of these can be estimated and incorporated into spatial conservation planning. However, there is limited information on the degree to which including this information affects conservation planning. We compared the performance of systematic conservation prioritizations for different scenarios based on varying the input species' distributions by ecological metric (abundance distributions versus range maps) and temporal sampling resolution (weekly, monthly, or quarterly). We used the example of a community of 41 species of migratory shorebirds that breed in North America, and we used eBird data to produce weekly estimates of species' abundances and ranges. Abundance distributions at a monthly or weekly resolution led to prioritizations that most efficiently protected species throughout the full annual cycle. Conversely, spatial prioritizations based on species' ranges required more sites and left most species insufficiently protected for at least part of their annual cycle. Prioritizations with only quarterly species ranges were very inefficient as they needed to target 40% of species' ranges to include 10% of populations. We highlight the high value of abundance information for spatial conservation planning, which leads to more efficient and effective spatial prioritization for conservation. Overall, we provide evidence that spatial conservation planning for wide-ranging migratory species is most robust and efficient when informed by species' abundance information from the full annual cycle.


Sujet(s)
Sélection , Conservation des ressources naturelles , Amérique du Nord , Dynamique des populations
2.
Steroids ; 142: 48-54, 2019 02.
Article de Anglais | MEDLINE | ID: mdl-29246492

RÉSUMÉ

Steroid-binding globulins (SBGs) such as sex hormone binding globulin, corticosteroid binding globulin, and vitamin-D binding protein are receiving increasing notice as being actively involved in steroid actions. This paper reviews data of all three of these SBGs, focusing on their presence and possible activity in the brain and nose. We have found all three proteins in the brain in limbic areas such as the paraventricular (PVN) and supraoptic nuclei (SON) as well as other areas of the hypothalamus, hippocampus, and medial preoptic area. There is also evidence that all three are made in the PVN and SON, in conjunction with the neuropeptides oxytocin and vasopressin. The localization of these three SBGs is more variable within areas of the main olfactory area and the vomeronasal organ. However, all three are found in the mucus of these areas, suggesting that one of their functions is to sequester aerosol steroids, such as pheromones, and deliver them to sensory cells and then to deeper sensory areas. In this manuscript, we present multiple models of SBG action including: A) SBG binding to a membrane receptor, B) this SBG receptor being associated with a larger protein complex including cytoplasmic steroid receptors, C) when the SBGs binds to their SBG receptors, second messengers within the cells respond, D) after SBG binding to its receptor, it releases its associated steroid into the membrane's lipid bilayer, from which it gains access into the cell only when bound by an internal protein, E) the SBG, possibly with its bound SBG receptor, is internalized into the cell from which it can gain access to numerous organelles and possibly the cell's nucleus or F) associate with intracellular steroid receptors, G) SBGs produced in target cells are released from those cells upon specific stimulation, and H) according to the Free Steroid Hypothesis steroids released from the extracellular SBG passively diffuse across the plasma membrane of the cell. These models move the area of steroid endocrinology forward by providing important paths of steroid activity within many steroid target cells.


Sujet(s)
Encéphale/métabolisme , Nez/composition chimique , Globuline de liaison aux hormones sexuelles/analyse , Globuline de liaison aux hormones sexuelles/métabolisme , Animaux , Humains
3.
Pathologe ; 38(5): 416-421, 2017 Sep.
Article de Allemand | MEDLINE | ID: mdl-28752179

RÉSUMÉ

BACKGROUND: The number of autopsies has been steadily declining worldwide over the past decades. The reasons for this are diverse. Legislation regarding opposition and consent rules does not appear to have had a significant impact on the autopsy rates. Above all, structural causes and the attitude of the medical profession are the reasons for this decline. The main argument for a high autopsy rate is the identification of diagnostic errors; however, diagnostic discrepancies are relatively independent of the rate of autopsies performed. At the University Hospital (UniversitätsSpital) Zurich it could be shown in a study that from 1972-2002 the frequency of relevant diagnostic discrepancies (classes I and II) decreased from 30% to 7%. OBJECTIVE: The aim of this article is to present the necessity of a stable autopsy rate and to examine the situation of the autopsy in Switzerland. MATERIAL AND METHODS: For this purpose, the importance of autopsies in the fields of quality assurance of medical diagnostics, cancer statistics, medical research as well as further education of doctors in Switzerland is shown. Efforts are being made by the pathologists to counteract the declining autopsy rates. RESULTS AND DISCUSSION: Declining autopsy numbers have a significant influence on cancer statistics. The rate of newly discovered tumors in autopsies in Switzerland decreased from 42% in 1980 to 17% in 2010. Pediatric autopsies are an important tool for quality assurance of medical diagnostics in neonatology and pediatrics in Switzerland, but the rate of autopsies carried out is also declining. Postmortem magnetic resonance imaging (MRI) examinations (virtopsy) could increase the acceptance of the parents for an autopsy in the future. Autopsies make an important contribution in research and in documentation of therapy-associated side effects and they are an important component of further education of the upcoming medical generations.


Sujet(s)
Autopsie/statistiques et données numériques , Attitude du personnel soignant , Autopsie/tendances , Diagnostic différentiel , Erreurs de diagnostic , Hôpitaux universitaires/statistiques et données numériques , Humains , Prévalence , Suisse
4.
J Chem Neuroanat ; 81: 42-47, 2017 04.
Article de Anglais | MEDLINE | ID: mdl-28159658

RÉSUMÉ

We studied the expression of vitamin D receptor and of vitamin D binding protein in the rat vomeronasal organ. With immunofluorescence, in situ hybridization and with reverse transcriptase PCR we found both proteins in sensory as well as in non-sensory cells. Sensory neurons contained immunoreactivity for vitamin D3 receptor in nuclei, in portions of the cytoplasm, and in apical dendrites and their microvilli. Vitamin D binding protein was observed in sensory neuron axons and cytoplasm, mostly confined to dendrites. Colocalization appeared in the contact zone of supporting cells and sensory dendrites. Both proteins were also found in single ciliated cells within the non-sensory epithelium. Vitamin D binding protein was also localized in secretory vesicles in a portion of the vomeronasal glands. Our findings suggest that the rat vomeronasal organ is a vitamin D target.


Sujet(s)
Systèmes de délivrance de médicaments , Récepteur calcitriol/métabolisme , Protéine de liaison à la vitamine D/métabolisme , Vitamine D/métabolisme , Organe voméronasal/métabolisme , Animaux , Systèmes de délivrance de médicaments/méthodes , Femelle , Mâle , Muqueuse olfactive/composition chimique , Muqueuse olfactive/effets des médicaments et des substances chimiques , Muqueuse olfactive/métabolisme , Rats , Rat Wistar , Récepteur calcitriol/analyse , Cellules réceptrices sensorielles/composition chimique , Cellules réceptrices sensorielles/effets des médicaments et des substances chimiques , Cellules réceptrices sensorielles/métabolisme , Vitamine D/administration et posologie , Protéine de liaison à la vitamine D/analyse , Organe voméronasal/composition chimique , Organe voméronasal/effets des médicaments et des substances chimiques
5.
J Chem Neuroanat ; 77: 19-23, 2016 11.
Article de Anglais | MEDLINE | ID: mdl-27085688

RÉSUMÉ

Olfactory marker protein (OMP) may act as a modulator within the olfactory signal-transduction cascade. It has also been shown to have some importance in development of olfactory sensory organs. Here we used high resolution immunocytochemistry to localize OMP in the rat vomeronasal organ (VNO). Immunofluorescence for OMP was abundant in cilia and in apical dendrites of sensory cells, mostly associated with intraepithelial capillaries. Perikarya were stained to a lesser extent while intense OMP immunoreactivity was seen in axons of sensory neurons. Single cells within the non-sensory portion of the VNO exhibited intense OMP immunofluorescence in apical cilia and weak cytoplasmic staining. Some of the exocrine cells in the vomeronasal glands contained OMP positive secretory granules. Electron microscopy revealed that non-sensory ciliated cells had short rod like kinocilia as well as microvilli. These cells contained secretory vesicles. Their basal portion was in close apposition to nerve endings. Our findings suggest that the sensory part of the VNO contains OMP positive sensory neurons and that the non-sensory epithelium may contain secondary sensory cells. In addition OMP may be liberated from secretory glands into vomeronasal secretions.


Sujet(s)
Protéine marqueur olfactif/biosynthèse , Organe voméronasal/métabolisme , Animaux , Vaisseaux capillaires/cytologie , Vaisseaux capillaires/métabolisme , Vaisseaux capillaires/ultrastructure , Cils vibratiles/métabolisme , Cils vibratiles/ultrastructure , Cytoplasme/métabolisme , Cytoplasme/ultrastructure , Dendrites/métabolisme , Dendrites/ultrastructure , Femelle , Immunohistochimie , Mâle , Protéine marqueur olfactif/génétique , Muqueuse olfactive/métabolisme , Muqueuse olfactive/ultrastructure , Rats , Rat Wistar , Cellules réceptrices sensorielles/métabolisme , Cellules réceptrices sensorielles/ultrastructure , Organe voméronasal/ultrastructure
6.
Rofo ; 177(1): 105-13, 2005 Jan.
Article de Allemand | MEDLINE | ID: mdl-15657828

RÉSUMÉ

PURPOSE: Microangiopathic lesions of the brain tissue correlate with the clinical diagnosis of vascular subcortical dementia. The "experience-based" evaluation is insufficient. Rating scales may contribute to reproducible quantification. MATERIALS AND METHODS: In MRI studies of 10 patients, 9 neuroradiologists quantified vascular white matter lesions (WMLs) at two different points in time for 12 anatomically defined regions with respect to number, size and localization (score). For 9 observers and 10 studies, 90 intra-observer differences were obtained for each of the 12 WML scores. To calculate the inter-observer reliability, rating pairs were formed. Furthermore, 360 differences were computed for each score and rating for 12 anatomically defined WML scores, and the intraclass correlation (ICC) was calculated as a measure of agreement (reliability). RESULTS: As to the intra-observer reliability, the median of the differences was 1.5 for the entire brain as opposed to 0 for defined brain regions. The corresponding values for the inter-observer reliability were 3 and 1, respectively. The mean intra-class correlation coefficient for the 10 studies was 0.88, whereas the mean interclass correlation concerning the inter-observer reliability was 0.70, with the first and second rating being averaged. The rating of each study took about 6 minutes. CONCLUSION: The rating scale with high intra- and inter-observer reliability can dependably quantify WMLs and correlates with the clinical diagnosis of vascular dementia. Using a reliable rating scale, the diagnostic distinction of age-associated physiological vs. pathological size of the WML can make a contribution to the reproducible quantifiable diagnostic evaluation of vascular brain tissue lesions within the framework of dementia diagnostics.


Sujet(s)
Encéphale/anatomopathologie , Démence vasculaire/diagnostic , Imagerie par résonance magnétique , Sujet âgé , Interprétation statistique de données , Démence vasculaire/anatomopathologie , Diagnostic différentiel , Femelle , Humains , Mâle , Adulte d'âge moyen , Biais de l'observateur , Facteurs temps
8.
Am J Med Genet ; 92(4): 260-3, 2000 Jun 05.
Article de Anglais | MEDLINE | ID: mdl-10842292

RÉSUMÉ

Serological and molecular (DNA-STR) analysis of a paternity case demonstrated exclusion of paternity of the presumptive father in two markers (ACP and Apo B, both localized on chromosome 2, region 2p25.2 and 2p23/24, respectively) in a phenotypically normal girl with a normal karyotype 46,XX (by GT-banding). The index of paternity calculated for other serological (seven erythrocyte antigens, six serum protein systems, and seven isozymes, as well as the A- and B-HLA loci) and nine DNA markers, excluding ACP and Apo B, gives a very high (virtually certain) degree of paternity for the presumptive father. Maternal uniparental disomy (UPD) for chromosome 2 was suspected. Evaluation of polymorphic DNA markers (STRs) spanning chromosome 2 of the child, mother, and presumptive father demonstrated that the girl had inherited two maternal chromosome 2 homologues, whereas alleles for markers from other chromosomes were inherited from the father in a Mendelian fashion. The girl was homoallelic for informative markers mapping to the chromosomal regions 2p23-25, but she was heteroallelic for informative markers on the long arm of chromosome 2, establishing that the maternal UPD with partial isodisomy of the short arm was caused by a meiosis I nondisjunction event with genetic recombination (chiasmata in this region 2p23-25) during oogenesis.


Sujet(s)
Aberrations des chromosomes , Chromosomes humains de la paire 2/génétique , Antigènes de groupe sanguin/génétique , Enfant d'âge préscolaire , Femelle , Marqueurs génétiques , Haplotypes , Humains , Mâle , Répétitions microsatellites
9.
Hum Biol ; 71(2): 231-44, 1999 Apr.
Article de Anglais | MEDLINE | ID: mdl-10222645

RÉSUMÉ

The red cell enzymes ACP1, ESD, GLO1, PGM1 and RDS and the serum proteins GC, HP, PI, and TF were determined for samples of 150 and 144 Sakha, respectively. The Sakha, a Turkic-speaking population, inhabit the Sakha-Yakutia Republic in northeastern Siberia. High gene frequencies were found for ACP1*A, GLO1*1 and GC*1F, whereas no P1*S or P1*Z alleles were found. In addition, 1 heterozygous phenotype with ACP1*C and 2 heterozygous phenotypes with ESD*7 were found. The genetic distance measures show close affinities of the Sakha population to Buryats (especially Western Buryats), Mongols, and Evenks, whereas the genetic distance to Turkic-speaking Altay and Tuvan populations is great.


Sujet(s)
Protéines du sang/génétique , Érythrocytes/enzymologie , Ethnies/génétique , Fréquence d'allèle/génétique , Émigration et immigration , Analyse statistique factorielle , Dépistage des porteurs génétiques , Humains , Phénotype , Sibérie
10.
Hum Biol ; 69(3): 357-73, 1997 Jun.
Article de Anglais | MEDLINE | ID: mdl-9164046

RÉSUMÉ

The Abbad are one of the largest tribes in Jordan with a complex structure dictated by historical and cultural factors. To study the genetic variability within the tribe, we examined four samples representing different levels of tribal structure for the polymorphisms of five blood groups, five erythrocyte enzymes, and seven serum proteins. The obtained allele distributions indicate a wide range of genetic variability within the tribe. An allelic heterogeneity test revealed significant differences between the examined samples, yet a gene diversity analysis revealed no significant substructuring. The observed genetic relationships among the four samples appear to agree with the tribal organization. Endogamous mating within the tribe and inbreeding within the subunits are believed to be the main factors that influenced the observed variability. This was confirmed by the results of the R matrix analysis, which summarized the genetic relationships in concordance with intertribal admixture, when affiliation and historical and maternal links were considered. The study is also an example of gene diffusion and of a negative relationship between the FY A-B- phenotype and endemicity of malaria.


Sujet(s)
Antigènes de groupe sanguin/génétique , Ethnies/génétique , Fréquence d'allèle/génétique , Hétérogénéité génétique , Variation génétique/génétique , Polymorphisme génétique/génétique , Adolescent , Adulte , Consanguinité , Humains , Jordanie , Mâle , Adulte d'âge moyen
11.
J Infect Dis ; 175(5): 1237-9, 1997 May.
Article de Anglais | MEDLINE | ID: mdl-9129094

RÉSUMÉ

Experimental immunoglobulin preparations for treatment of group B streptococcal (GBS) infections contain low levels of functional antibody and exhibit lot-to-lot variability. GBS capsular polysaccharide-protein conjugate vaccines have recently been shown to produce high serum levels of type-specific antibody in healthy volunteers. Treatment of neonatal mice 4 h after inoculation with an ordinarily lethal dose of GBS type Ia, Ib, or III with pooled human serum from adults who had received GBS type Ia capsular polysaccharide-tetanus toxoid vaccine (Ia CPS-TT), Ib CPS-TT, or III CPS-TT resulted in 63%, 70%, and 75% survival, respectively. In contrast, < or = 17% of the infected mice treated with normal human serum or saline survived. These results demonstrate the therapeutic activity of GBS polysaccharide conjugate vaccine-induced antiserum and provide a rationale for the use of these vaccines in producing a functional, high-titered intravenous immunoglobulin preparation for clinical use.


Sujet(s)
Vaccins antibactériens , Immunisation passive , Immunoglobulines par voie veineuse/usage thérapeutique , Infections à streptocoques/immunologie , Infections à streptocoques/prévention et contrôle , Vaccins antistreptococciques , Streptococcus agalactiae/immunologie , Vaccins synthétiques , Adulte , Animaux , Animaux nouveau-nés , Production d'anticorps , Capsules bactériennes , Humains , Lipopolysaccharides/immunologie , Souris , Infections à streptocoques/sang , Anatoxine tétanique/immunologie
12.
Hum Biol ; 69(1): 41-57, 1997 Feb.
Article de Anglais | MEDLINE | ID: mdl-9037894

RÉSUMÉ

Genetic variations of four highly polymorphic serum proteins, TF, PI, F13B, and AHSG, were tested to distinguish one black African and one Khoisan population of southwest Africa. The results show that indeed the systems TF, PI, and AHSG are of high value for anthropological genetics: The allele frequencies for these systems enable clear identification of and distinction between black African and Khoisan populations. The F13B locus, on the other hand, reveals for both the black African and the Khoisan populations specific and unique African variants: a high frequency of F13B*2 and the lowest frequency of F13B*3 so far worldwide. The new data are compared with results for TF and PI in another black African population of Mozambique, which Rodewald et al. (1988) had studied previously. The dendrogram, based on genetic distance data D and average linkage cluster analysis, shows minimal distance between both black African populations of Namibia and Mozambique and marked distance between those and the Khoisan population of Namibia.


Sujet(s)
Protéines du sang/génétique , Ethnies/génétique , Polymorphisme génétique , Allèles , Analyse de regroupements , Fréquence d'allèle , Variation génétique , Humains , Mozambique , Namibie
13.
Hum Biol ; 68(6): 929-53, 1996 Dec.
Article de Anglais | MEDLINE | ID: mdl-8979465

RÉSUMÉ

We evaluate the pattern of genetic variation among native Mesoamerican Amerindians by the construction of a gene frequency map that reflects the past action of evolutionary forces. The analysis is based on the theory that genes of modern human populations carry the encoded history even of humans' remote past and their early wanderings around the globe. We examined the serum proteins TF, PI, F13B and AHSG on 491 samples of 6 Mesoamerican Amerindian tribes (Guaymi, Bribri, Cabecar, Teribe, Guatuso, and Huetar) and 2 tribal mixed samples (Teribe x Guaymi and Bribri x Cabecar). We find a distinct genetic pattern in the examined tribes that clearly separates the Mesoamerican Amerindians from other living Amerindian groups. The proteins, TF, PI, and AHSG proved to be especially rich in special genetically fixed variants and polymorphisms, and F13B proved to be a powerful genetic marker to distinguish human groups. Using Nei's distance D and Mahalanobis's D2, we compared the polymorphisms and allele frequencies at the four serum protein loci to discern degrees of similarity between the samples. These data are presented in the dendrograms computed by average linkage cluster analyses and in two kinds of unrooted phylogenetic trees, neighbor-joining trees and split decompositions. Estimations are made on Hardy-Weinberg equilibrium and on genetic diversity and average heterozygosity index.


Sujet(s)
Protéines du sang/génétique , Ethnies/génétique , Génétique des populations , Protéines du sang/analyse , Amérique centrale , Humains
14.
Anthropol Anz ; 54(2): 117-20, 1996 Jun.
Article de Anglais | MEDLINE | ID: mdl-8767722

RÉSUMÉ

Genetic polymorphism of the PLG serum protein was examined in the Namibian !Kung San and Kavango (Bantu) populations by means of IEF technique. The two samples revealed very similar allele frequencies (!Kung San: PLG*A = 0.8351, PLG*B = 0.1649; Kavango: PLG*A = 0.8228, PLG*B = 0.1732 and PLG*M4 = 0.004). The Namibian distributions were within previously observed African PLG ranges. The effects of natural selection were also discussed.


Sujet(s)
Ethnies/génétique , Génétique des populations , Plasminogène/génétique , Polymorphisme génétique/génétique , Adulte , Allèles , Comparaison interculturelle , Fréquence d'allèle/génétique , Humains , Focalisation isoélectrique , Mâle , Namibie , Phénotype , Sélection génétique
15.
Anthropol Anz ; 53(2): 133-5, 1995 Jun.
Article de Anglais | MEDLINE | ID: mdl-7668842

RÉSUMÉ

The distribution of the HP and GC serum protein polymorphisms in the !Kung San and Kavango (Bantu) populations in Namibia were examined. The obtained allele frequencies of GC marker system were very similar in both populations (GC*1F approximately equal to 0.80, GC*2 approximately equal to 0.10), while the distributions of the HP subtypes in the !Kung San sample (HP*1F = 0.0967, HP*1S = -.1452, HP*2FS = 0.7581) differed markedly from those in the Kavango one (HP*1F = 0.3791, HP*1S = 0.2375, HP*2S = 0.375). These results confirm previously reported allelic distributions in ethnically similar populations.


Sujet(s)
/génétique , Marqueurs génétiques/génétique , Haptoglobines/génétique , Hawaïen autochtone ou autre insulaire du Pacifique/génétique , Polymorphisme génétique/génétique , Protéine de liaison à la vitamine D/génétique , Adulte , Allèles , Fréquence d'allèle/génétique , Génétique des populations , Humains , Mâle , Namibie , Phénotype ,
16.
Hum Hered ; 44(6): 316-21, 1994.
Article de Anglais | MEDLINE | ID: mdl-7860084

RÉSUMÉ

Two samples representing the Moslem and Christian communities of Jordan were examined for the polymorphic serum proteins AHSG, BF, FXIIIB, GC, HP, PI, PLG, and TF. The results revealed similar allele distributions, and low interpopulation differentiation (GST = 0.0004) between the two communities. The low HP*1S (< 0.12) allele frequencies and the comparatively high PLG*B (> 0.40) and BF*S.07 (approximately equal to 0.05) frequencies are characteristic of the populations of this region.


Sujet(s)
Protéines du sang/analyse , Polymorphisme génétique/génétique , Adolescent , Adulte , Enfant , Christianisme , Femelle , Fréquence d'allèle , Humains , Islam , Focalisation isoélectrique , Jordanie , Mâle , Adulte d'âge moyen , /génétique
17.
Am J Med Genet ; 53(3): 227-35, 1994 Nov 15.
Article de Anglais | MEDLINE | ID: mdl-7856657

RÉSUMÉ

The dermatoglyphic patterns of fingertips and palms of 115 patients with Williams-Beuren syndrome (WBS) were analysed and compared with the data from 199 control individuals from Germany. The following combination of dermatoglyphic patterns appears to be characteristic to WBS: an excess of whorls on all fingertips; high termination values of the main lines D, B, and A; frequent absence of C triradius (C0); high frequencies of ulnar loops on the hypothenar and distal loops on the 2nd, 3rd, and 4th interdigital areas, of distal axial triradii t", and of abnormal palmar creases such as simian crease and Sydney lines. The combination of fingertip and palmar patterns expressed by a "Log.Score-Index," provides a high degree of discrimination between the WBS patients (92%) and the control group (88%). A "phantom picture" for WBS was constructed, which can be used for its diagnosis.


Sujet(s)
Malformations multiples/génétique , Dermatoglyphes , Malformations multiples/diagnostic , Malformations multiples/anatomopathologie , Études cas-témoins , Loi du khi-deux , Face/malformations , Femelle , Gènes dominants , Cardiopathies congénitales/diagnostic , Cardiopathies congénitales/génétique , Humains , Déficience intellectuelle/diagnostic , Déficience intellectuelle/génétique , Modèles logistiques , Mâle , Syndrome
18.
Infect Immun ; 62(8): 3236-43, 1994 Aug.
Article de Anglais | MEDLINE | ID: mdl-8039893

RÉSUMÉ

Most cases of neonatal sepsis and meningitis caused by group B streptococci (GBS) are attributable to one of four major capsular serotypes: Ia, Ib, II, or III. Because resistance to infection with GBS has been correlated with the presence of serum antibodies to the type-specific capsular polysaccharides in both experimental animals and human neonates, efforts have been made to elicit protective immunity with GBS capsular polysaccharide vaccines. However, the GBS capsular polysaccharides alone are not highly immunogenic in either animals or human volunteers. Therefore, we and other investigators have attempted to enhance immunogenicity by coupling individual capsular polysaccharides to a carrier protein. Here we report the synthesis and immunogenicity in rabbits of a GBS type Ib polysaccharide-tetanus toxoid vaccine prepared by the direct, covalent attachment of tetanus toxoid to a selected number of sialic acid residues on the type-specific polysaccharide. In addition, the Ib polysaccharide-tetanus toxoid conjugate vaccine was combined with similar tetanus toxoid conjugates of GBS type Ia, II, and III polysaccharides to form a tetravalent GBS conjugate vaccine. Protective efficacy of the GBS tetravalent conjugate vaccine was demonstrated in a mouse maternal immunization-neonatal challenge model of GBS infection. The results support testing in human subjects of a multivalent GBS conjugate vaccine of this design, with the eventual goal of protecting newborns against GBS infection.


Sujet(s)
Vaccins antibactériens/immunologie , Immunité acquise d'origine maternelle , Polyosides bactériens/immunologie , Infections à streptocoques/prévention et contrôle , Streptococcus agalactiae/immunologie , Anatoxine tétanique/immunologie , Animaux , Animaux nouveau-nés , Séquence glucidique , Femelle , Sérums immuns/immunologie , Souris , Données de séquences moléculaires , Phagocytose , Lapins , Vaccination , Vaccins conjugués/immunologie
19.
Rev Med Chil ; 122(6): 653-9, 1994 Jun.
Article de Espagnol | MEDLINE | ID: mdl-7732209

RÉSUMÉ

The aim this work was to assess and compare the achievements of medical students, subjected to problem based learning methodology. The information and comprehension categories of Bloom were tested in 17 medical students in four different occasions during the physiopathology course, using a multiple choice knowledge test. There was a significant improvement in the number of correct answers towards the end of the course. It is concluded that these medical students obtained adequate learning achievements in the information subcategory of Bloom using problem based learning methodology, during the physiopathology course.


Sujet(s)
Enseignement médical premier cycle/méthodes , Évaluation des acquis scolaires , Apprentissage par problèmes , Évaluation des acquis scolaires/méthodes
20.
Infect Immun ; 61(11): 4760-6, 1993 Nov.
Article de Anglais | MEDLINE | ID: mdl-8406875

RÉSUMÉ

Antisera elicited by type Ia group B streptococci (GBS) contain antibodies that react with both type Ia and type Ib strains. Previous studies suggested that antibodies elicited by type Ia organisms recognized a carbohydrate antigen or epitope common to Ia and Ib strains. We now report the synthesis and immunogenicity testing of a type Ia polysaccharide-tetanus toxoid (Ia-TT) conjugate vaccine. Ia-TT elicited type Ia polysaccharide-specific immunoglobulin G antibodies in all three of the rabbits inoculated. In competitive enzyme-linked immunosorbent assay, these antibodies reacted with high affinity to type Ia polysaccharide and with lower affinity to the structurally related GBS type Ib polysaccharide. Despite the lower binding affinity of the Ia-TT-induced antibodies for the type Ib polysaccharide, Ia-TT antiserum opsonized not only type Ia GBS but also type Ib GBS for killing by human blood leukocytes. Ia-TT antiserum was also evaluated in a mouse model designed to test the efficacy of maternal antibodies in protecting neonates against GBS infection. Pups born to dams that had received Ia-TT antiserum were protected against lethal challenge with either type Ia or Ib GBS. These studies using a polysaccharide-protein conjugate as an immunogen support the view that the carbohydrate immunodeterminant recognized on Ib strains by Ia antisera is a common epitope contained within the structurally related Ia and Ib capsular polysaccharides. Although antibodies elicited by Ia-TT had protective activity against both Ia and Ib strains, these antibodies reacted with lower affinity to Ib than to Ia polysaccharide.


Sujet(s)
Anticorps antibactériens/immunologie , Vaccins antibactériens/immunologie , Polyosides bactériens/immunologie , Streptococcus agalactiae/immunologie , Anatoxine tétanique/immunologie , Animaux , Séquence glucidique , Sérums immuns/immunologie , Données de séquences moléculaires , Phagocytose , Lapins , Infections à streptocoques/prévention et contrôle , Vaccins conjugués/immunologie
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