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1.
Front Oncol ; 13: 1147591, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37143941

RESUMEN

Introduction: Lynch syndrome-associated cancer develops due to germline pathogenic variants in one of the mismatch repair (MMR) genes, MLH1, MSH2, MSH6 or PMS2. Somatic second hits in tumors cause MMR deficiency, testing for which is used to screen for Lynch syndrome in colorectal cancer and to guide selection for immunotherapy. Both MMR protein immunohistochemistry and microsatellite instability (MSI) analysis can be used. However, concordance between methods can vary for different tumor types. Therefore, we aimed to compare methods of MMR deficiency testing in Lynch syndrome-associated urothelial cancers. Methods: Ninety-seven urothelial (61 upper tract and 28 bladder) tumors diagnosed from 1980 to 2017 in carriers of Lynch syndrome-associated pathogenic MMR variants and their first-degree relatives (FDR) were analyzed by MMR protein immunohistochemistry, the MSI Analysis System v1.2 (Promega), and an amplicon sequencing-based MSI assay. Two sets of MSI markers were used in sequencing-based MSI analysis: a panel of 24 and 54 markers developed for colorectal cancer and blood MSI analysis, respectively. Results: Among the 97 urothelial tumors, 86 (88.7%) showed immunohistochemical MMR loss and 68 were successfully analyzed by the Promega MSI assay, of which 48 (70.6%) were MSI-high and 20 (29.4%) were MSI-low/microsatellite stable. Seventy-two samples had sufficient DNA for the sequencing-based MSI assay, of which 55 (76.4%) and 61 (84.7%) scored as MSI-high using the 24-marker and 54-marker panels, respectively. The concordance between the MSI assays and immunohistochemistry was 70.6% (p = 0.003), 87.5% (p = 0.039), and 90.3% (p = 1.00) for the Promega assay, the 24-marker assay, and the 54-marker assay, respectively. Of the 11 tumors with retained MMR protein expression, four were MSI-low/MSI-high or MSI-high by the Promega assay or one of the sequencing-based assays. Conclusion: Our results show that Lynch syndrome-associated urothelial cancers frequently had loss of MMR protein expression. The Promega MSI assay was significantly less sensitive, but the 54-marker sequencing-based MSI analysis showed no significant difference compared to immunohistochemistry. Data from this study alongside previous studies, suggest that universal MMR deficiency testing of newly diagnosed urothelial cancers, using immunohistochemistry and/or sequencing-based MSI analysis of sensitive markers, offer a potentially useful approach to identification of Lynch syndrome cases.

2.
Gastroenterology ; 164(4): 579-592.e8, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36586540

RESUMEN

BACKGROUND & AIMS: Constitutional mismatch repair deficiency (CMMRD) is a rare recessive childhood cancer predisposition syndrome caused by germline mismatch repair variants. Constitutional microsatellite instability (cMSI) is a CMMRD diagnostic hallmark and may associate with cancer risk. We quantified cMSI in a large CMMRD patient cohort to explore genotype-phenotype correlations using novel MSI markers selected for instability in blood. METHODS: Three CMMRD, 1 Lynch syndrome, and 2 control blood samples were genome sequenced to >120× depth. A pilot cohort of 8 CMMRD and 38 control blood samples and a blinded cohort of 56 CMMRD, 8 suspected CMMRD, 40 Lynch syndrome, and 43 control blood samples were amplicon sequenced to 5000× depth. Sample cMSI score was calculated using a published method comparing microsatellite reference allele frequencies with 80 controls. RESULTS: Thirty-two mononucleotide repeats were selected from blood genome and pilot amplicon sequencing data. cMSI scoring using these MSI markers achieved 100% sensitivity (95% CI, 93.6%-100.0%) and specificity (95% CI 97.9%-100.0%), was reproducible, and was superior to an established tumor MSI marker panel. Lower cMSI scores were found in patients with CMMRD with MSH6 deficiency and patients with at least 1 mismatch repair missense variant, and patients with biallelic truncating/copy number variants had higher scores. cMSI score did not correlate with age at first tumor. CONCLUSIONS: We present an inexpensive and scalable cMSI assay that enhances CMMRD detection relative to existing methods. cMSI score is associated with mismatch repair genotype but not phenotype, suggesting it is not a useful predictor of cancer risk.


Asunto(s)
Neoplasias Encefálicas , Neoplasias Colorrectales Hereditarias sin Poliposis , Neoplasias Colorrectales , Síndromes Neoplásicos Hereditarios , Humanos , Neoplasias Colorrectales Hereditarias sin Poliposis/genética , Inestabilidad de Microsatélites , Síndromes Neoplásicos Hereditarios/diagnóstico , Síndromes Neoplásicos Hereditarios/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/diagnóstico , Neoplasias Encefálicas/diagnóstico , Genotipo , Reparación de la Incompatibilidad de ADN/genética , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto/genética
4.
Cancers (Basel) ; 14(15)2022 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-35954501

RESUMEN

Identification of mismatch repair (MMR)-deficient colorectal cancers (CRCs) is recommended for Lynch syndrome (LS) screening, and supports targeting of immune checkpoint inhibitors. Microsatellite instability (MSI) analysis is commonly used to test for MMR deficiency. Testing biopsies prior to tumour resection can inform surgical and therapeutic decisions, but can be limited by DNA quantity. MSI analysis of voided urine could also provide much needed surveillance for genitourinary tract cancers in LS. Here, we reconfigure an existing molecular inversion probe-based MSI and BRAF c.1799T > A assay to a multiplex PCR (mPCR) format, and demonstrate that it can sample >140 unique molecules per marker from <1 ng of DNA and classify CRCs with 96−100% sensitivity and specificity. We also show that it can detect increased MSI within individual and composite CRC biopsies from LS patients, and within preoperative urine cell free DNA (cfDNA) from two LS patients, one with an upper tract urothelial cancer, the other an undiagnosed endometrial cancer. Approximately 60−70% of the urine cfDNAs were tumour-derived. Our results suggest that mPCR sequence-based analysis of MSI and mutation hotspots in CRC biopsies could facilitate presurgery decision making, and could enable postal-based screening for urinary tract and endometrial tumours in LS patients.

6.
Parasitol Res ; 120(10): 3497-3505, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34490523

RESUMEN

Understanding parasite-host ecology is increasingly important for conservation efforts in a changing world. Parasitic nest flies in the genus Philornis (Diptera: Muscidae) have been implicated in the decline of endemic island species and are also known to negatively impact breeding success of the critically endangered Ridgway's hawk (B. ridgwayi) on the island of Hispaniola. Despite the importance of these effects on hosts, and extensive research of Philornis downsi in the Galápagos, the ecology of most species of philornid nest flies is poorly understood. We examined biotic factors related to Philornis pici infestations of nestling Ridgway's hawks in the Dominican Republic, where both fly and hawk are native. We found grass-cover was negatively associated with P. pici infestations, while coverage and height of other vegetation classes (tree, shrub, herbaceous, and bare ground) had no association, which is interesting considering recent landscape-level changes to Ridgway's hawk habitat. Anthropogenic activities in Los Haitises National Park, the last strong-hold of Ridgway's hawk, have shifted the landscape from primary forest to a fragmented secondary forest with smallholder or subsistence farms and grassy patches. New information on the ecology of nest flies in their native habitat can inform conservation efforts and allow us to make recommendations for future research.


Asunto(s)
Muscidae , Miasis , Parásitos , Animales , Ecosistema , Fitomejoramiento
7.
Cancers (Basel) ; 13(3)2021 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-33499123

RESUMEN

International guidelines for the diagnosis of Lynch syndrome (LS) recommend molecular screening of colorectal cancers (CRCs) to identify patients for germline mismatch repair (MMR) gene testing. As our understanding of the LS phenotype and diagnostic technologies have advanced, there is a need to review these guidelines and new screening opportunities. We discuss the barriers to implementation of current guidelines, as well as guideline limitations, and highlight new technologies and knowledge that may address these. We also discuss alternative screening strategies to increase the rate of LS diagnoses. In particular, the focus of current guidance on CRCs means that approximately half of Lynch-spectrum tumours occurring in unknown male LS carriers, and only one-third in female LS carriers, will trigger testing for LS. There is increasing pressure to expand guidelines to include molecular screening of endometrial cancers, the most frequent cancer in female LS carriers. Furthermore, we collate the evidence to support MMR deficiency testing of other Lynch-spectrum tumours to screen for LS. However, a reliance on tumour tissue limits preoperative testing and, therefore, diagnosis prior to malignancy. The recent successes of functional assays to detect microsatellite instability or MMR deficiency in non-neoplastic tissues suggest that future diagnostic pipelines could become independent of tumour tissue.

8.
Am J Bot ; 108(1): 91-101, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33349932

RESUMEN

PREMISE: The xylem tissue of plants performs three principal functions: transport of water, support of the plant body, and nutrient storage. Tradeoffs may arise because different structural requirements are associated with different functions or because suites of traits are under selection that relate to resource acquisition, use, and turnover. The structural and functional basis of xylem storage is not well established. We hypothesized that greater starch storage would be associated with greater sapwood parenchyma and reduced fibers, which would compromise resistance to xylem tensions during dehydration. METHODS: We measured cavitation resistance, minimum water potential, starch content, and sapwood parenchyma and fiber area in 30 species of southern California chaparral shrubs (evergreen and deciduous). RESULTS: We found that species storing greater starch within their xylem tended to avoid dehydration and were less cavitation resistant, and this was supported by phylogenetic independent contrasts. Greater sapwood starch was associated with greater parenchyma area and reduced fiber area. For species without living fibers, the associations with parenchyma were stronger, suggesting that living fibers may expand starch storage capacity while also contributing to the support function of the vascular tissue. Drought-deciduous species were associated with greater dehydration avoidance than evergreens. CONCLUSIONS: Evolutionary forces have led to an association between starch storage and dehydration resistance as part of an adaptive suite of traits. We found evidence for a tradeoff between tissue mechanical traits and starch storage; moreover, the evolution of novel strategies, such as starch-storing living fibers, may mitigate the strength of this tradeoff.


Asunto(s)
Sequías , Almidón , Deshidratación , Humanos , Filogenia , Agua , Xilema
9.
Parasitol Res ; 119(7): 2337-2342, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32500371

RESUMEN

Philornis flies Meinert (Diptera: Muscidae) have been documented parasitizing over 250 bird species, some of which are endemic species threatened with extinction. Philornis parasitism is hypothesized to affect nestlings disproportionately more than adult birds because limited mobility and exposed skin of nestlings increase their vulnerability to parasitism. We used a comprehensive literature review and our recent fieldwork in the Dominican Republic, Puerto Rico, and Grenada to challenge the idea that parasitism by subcutaneous Philornis species is a phenomenon primarily found in nestlings, a fact that has not been quantified to date. Of the 265 reviewed publications, 125 (49%) reported incidences of parasitism by subcutaneous Philornis, but only 12 included the sampling of adult breeding birds. Nine of these publications (75%) reported Philornis parasitism in adults of ten bird species. During fieldwork in the Dominican Republic, Puerto Rico, and Grenada, we documented 14 instances of parasitism of adult birds of seven avian species. From literature review and fieldwork, adults of at least fifteen bird species across 12 families and four orders of birds were parasitized by at least five Philornis species. In both the published literature and fieldwork, incidences of parasitism of adult birds occurred predominantly in females and was frequently associated with incubation. Although our findings indicate that Philornis parasitism of adult birds is more common than widely presumed, parasite prevalence is still greater in nestlings. In the future, we recommend surveys of adult birds to better understand host-Philornis relationships across life stages. This information may be essential for the development of effective control measures of Philornis to ensure the long-term protection of bird species of conservation concern.


Asunto(s)
Aves/parasitología , Muscidae/fisiología , Animales , Aves/clasificación , Femenino , Incidencia , Larva/clasificación , Larva/fisiología , Masculino , Muscidae/clasificación , Comportamiento de Nidificación , Prevalencia , Indias Occidentales/epidemiología
10.
Am J Occup Ther ; 74(3): 7403205030p1-7403205030p11, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32365309

RESUMEN

IMPORTANCE: Transition and integration reentry services continue to grow in carceral settings; however, related provision of occupational therapy is limited. OBJECTIVE: To examine the implementation fidelity of an occupational therapy-administered interprofessional reentry program initiated in an urban jail. DESIGN: Retrospective, mixed quantitative and qualitative design. SETTING: Community-based reentry services provided prerelease in a Midwestern urban jail and postrelease in the local St. Louis community. PARTICIPANTS: Occupational therapy practitioners tracking process measures for identifying reentry project feasibility. INTERVENTION: Provision of recruitment, assessment, and skilled occupational therapy services with people held in a short-term jail facility and follow-up during community reentry. OUTCOME AND MEASURES: Detailed logs were analyzed to describe attendance at and duration of sessions. We coded barriers to and facilitators of implementation from weekly team meeting notes and logs using social-ecological categories. RESULTS: Findings indicate that it was feasible to implement prerelease jail-based services (N = 63) because of jail operations and community partnerships (facilitators) and to overcome institutional policies and environmental limitations (barriers). Full 8-wk prerelease programming was completed by 38% (n = 24) of participants, and 52% (n = 33) participated less than 8 wk. All who completed the full prerelease program and transitioned to the community (n = 15) initiated postrelease occupational therapy services. CONCLUSIONS AND RELEVANCE: The iterative feedback provided by process evaluation supported the feasibility of implementing the jail-based Occupational Therapy Transition and Integration Services program. WHAT THIS ARTICLE ADDS: This process evaluation provides evidence that implementation of an occupational therapy-based transition program in an urban jail is feasible.


Asunto(s)
Terapia Ocupacional , Prisioneros , Evaluación de Programas y Proyectos de Salud , Humanos , Estudios Retrospectivos
11.
Hum Mutat ; 41(1): 332-341, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31471937

RESUMEN

Microsatellite instability (MSI) testing of colorectal cancers (CRCs) is used to screen for Lynch syndrome (LS), a hereditary cancer-predisposition, and can be used to predict response to immunotherapy. Here, we present a single-molecule molecular inversion probe and sequencing-based MSI assay and demonstrate its clinical validity according to existing guidelines. We amplified 24 microsatellites in multiplex and trained a classifier using 98 CRCs, which accommodates marker specific sensitivities to MSI. Sample classification achieved 100% concordance with the MSI Analysis System v1.2 (Promega) in three independent cohorts, totaling 220 CRCs. Backward-forward stepwise selection was used to identify a 6-marker subset of equal accuracy to the 24-marker panel. Assessment of assay detection limits showed that the 24-marker panel is marginally more robust to sample variables than the 6-marker subset, detecting as little as 3% high levels of MSI DNA in sample mixtures, and requiring a minimum of 10 template molecules to be sequenced per marker for >95% accuracy. BRAF c.1799 mutation analysis was also included to streamline LS testing, with all c.1799T>A variants being correctly identified. The assay, therefore, provides a cheap, robust, automatable, and scalable MSI test with internal quality controls, suitable for clinical cancer diagnostics.


Asunto(s)
Marcadores Genéticos , Predisposición Genética a la Enfermedad , Pruebas Genéticas , Ensayos Analíticos de Alto Rendimiento , Inestabilidad de Microsatélites , Repeticiones de Microsatélite , Alelos , Biomarcadores de Tumor , Línea Celular , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética , Reparación de la Incompatibilidad de ADN , Estudios de Asociación Genética/métodos , Pruebas Genéticas/métodos , Pruebas Genéticas/normas , Genotipo , Secuenciación de Nucleótidos de Alto Rendimiento , Ensayos Analíticos de Alto Rendimiento/métodos , Ensayos Analíticos de Alto Rendimiento/normas , Humanos , Técnicas de Diagnóstico Molecular , Fosforilación , Reproducibilidad de los Resultados
12.
Hum Mutat ; 40(5): 649-655, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30740824

RESUMEN

Constitutional mismatch repair deficiency (CMMRD) is caused by germline pathogenic variants in both alleles of a mismatch repair gene. Patients have an exceptionally high risk of numerous pediatric malignancies and benefit from surveillance and adjusted treatment. The diversity of its manifestation, and ambiguous genotyping results, particularly from PMS2, can complicate diagnosis and preclude timely patient management. Assessment of low-level microsatellite instability in nonneoplastic tissues can detect CMMRD, but current techniques are laborious or of limited sensitivity. Here, we present a simple, scalable CMMRD diagnostic assay. It uses sequencing and molecular barcodes to detect low-frequency microsatellite variants in peripheral blood leukocytes and classifies samples using variant frequencies. We tested 30 samples from 26 genetically-confirmed CMMRD patients, and samples from 94 controls and 40 Lynch syndrome patients. All samples were correctly classified, except one from a CMMRD patient recovering from aplasia. However, additional samples from this same patient tested positive for CMMRD. The assay also confirmed CMMRD in six suspected patients. The assay is suitable for both rapid CMMRD diagnosis within clinical decision windows and scalable screening of at-risk populations. Its deployment will improve patient care, and better define the prevalence and phenotype of this likely underreported cancer syndrome.


Asunto(s)
Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/genética , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética , Reparación de la Incompatibilidad de ADN , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Leucocitos/metabolismo , Inestabilidad de Microsatélites , Síndromes Neoplásicos Hereditarios/diagnóstico , Síndromes Neoplásicos Hereditarios/genética , Alelos , Estudios de Asociación Genética/métodos , Mutación de Línea Germinal , Humanos , Repeticiones de Microsatélite
13.
Immunobiology ; 223(1): 125-134, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29017821

RESUMEN

The use of C3d, the final degradation product of complement protein C3, as a "natural" adjuvant has been widely examined since the initial documentation of its immunogenicity-enhancing properties as a consequence of binding to complement receptor 2. Subsequently it was demonstrated that these effects are most evident when oligomeric, rather than when monomeric forms of C3d, are linked to various test protein antigens. In this study, we examined the feasibility of enhancing the adjuvant properties of human C3d further by utilizing C4b-binding protein (C4BP) to provide an oligomeric arrayed scaffold fused to the model antigen, tetanus toxin C fragment (TTCF). High molecular weight, C3d-containing oligomeric vaccines were successfully expressed, purified from mammalian cells and used to immunize groups of mice. Surprisingly, anti-TTCF antibody responses measured in these mice were poor. Subsequently we established by in vitro and in vivo analysis that, in the presence of mouse C3, human C3d does not interact with either mouse or even human complement receptor 2. These data confirm the requirement to develop murine versions of C3d based adjuvant compounds to test in mice or that mice would need to be developed that express both human C3 and human CR2 to allow the testing of human C3d based adjuvants in mouse in any capacity.


Asunto(s)
Linfocitos B/fisiología , Complemento C3d/inmunología , Proteína de Unión al Complemento C4b/genética , Fragmentos de Péptidos/inmunología , Toxina Tetánica/inmunología , Vacunas Sintéticas/inmunología , Adyuvantes Inmunológicos , Animales , Anticuerpos/sangre , Línea Celular , Complemento C3d/genética , Proteína de Unión al Complemento C4b/inmunología , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Animales , Fragmentos de Péptidos/genética , Multimerización de Proteína/genética , Receptores de Complemento 3d/genética , Receptores de Complemento 3d/metabolismo , Toxina Tetánica/genética , Vacunación , Vacunas Sintéticas/genética
14.
Ann Bot ; 113(4): 629-41, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24366109

RESUMEN

BACKGROUND AND AIMS: Pterostylis is an Australasian terrestrial orchid genus of more than 400 species, most of which use a motile, touch-sensitive labellum to trap dipteran pollinators. Despite studies dating back to 1872, the mechanism of pollinator attraction has remained elusive. This study tested whether the fungus gnat-pollinated Pterostylis sanguinea secures pollination by sexual deception. METHODS: The literature was used to establish criteria for confirming sexual deception as a pollination strategy. Observations and video recordings allowed quantification of each step of the pollination process. Each floral visitor was sexed and DNA barcoding was used to evaluate the degree of pollinator specificity. Following observations that attraction to the flowers is by chemical cues, experimental dissection of flowers was used to determine the source of the sexual attractant and the effect of labellum orientation on sexual attraction. Fruit set was quantified for 19 populations to test for a relationship with plant density and population size. KEY RESULTS: A single species of male gnat (Mycetophilidae) visited and pollinated the rewardless flowers. The gnats often showed probing copulatory behaviour on the labellum, leading to its triggering and the temporary entrapment of the gnat in the flower. Pollen deposition and removal occurred as the gnat escaped from the flower via the reproductive structures. The labellum was the sole source of the chemical attractant. Gnats always alighted on the labellum facing upwards, but when it was rotated 180 ° they attempted copulation less frequently. Pollination rate showed no relationship with orchid population size or plant density. CONCLUSIONS: This study confirms for the first time that highly specific pollination by fungus gnats is achieved by sexual deception in Pterostylis. It is predicted that sexual deception will be widespread in the genus, although the diversity of floral forms suggests that other mechanisms may also operate.


Asunto(s)
Dípteros/fisiología , Orchidaceae/fisiología , Animales , Código de Barras del ADN Taxonómico , Dípteros/clasificación , Dípteros/genética , Flores/fisiología , Frutas/fisiología , Hongos , Masculino , Polen/fisiología , Polinización , Reproducción , Especificidad de la Especie
15.
Mol Immunol ; 52(3-4): 200-6, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22721707

RESUMEN

Factor H autoantibodies are found in ~10% of aHUS patients. Most are associated with complete deficiency of factor H related proteins 1/3 and bind to the C terminal recognition domain. MPGN, like aHUS, is characterised by complement activation. In this study we, therefore, examined the hypothesis that factor H autoantibodies are associated with MPGN. We screened sera from 16 MPGN patients and 100 normal controls using ELISA and detected strongly positive IgG factor H autoantibodies in 2 patients. One patient had type II (DDD) MPGN (male aged 24 yrs) with C3NeF and the other type I (female aged 26 yrs) with no detectable C3NeF. We identified the binding site of the autoantibodies using small SCR domain fragments in the ELISA and showed that the autoantibodies in both patients bound predominately to the N terminal complement regulatory domain of factor H. We measured CFHR 1/3 copy number using MLPA and showed that both patients had 2 copies of CFHR1 and 3. Finally, we examined the functionality of detected factor H autoantibodies using purified patient IgG and observed increased haemolysis when purified IgG from both patients was added to normal human sera prior to incubation with rabbit red blood cells. Thus, in a cohort of MPGN patients we have found a high titre of functionally significant factor H autoantibodies in two patients with MPGN. Antibody depleting therapy may have a role in such patients and we suggest that screening for factor H autoantibodies should be undertaken in all patients with MPGN.


Asunto(s)
Autoanticuerpos/sangre , Autoanticuerpos/inmunología , Factor H de Complemento/inmunología , Glomerulonefritis Membranoproliferativa/inmunología , Adolescente , Adulto , Anciano , Sitios de Unión de Anticuerpos , Complemento C3 , Factor Nefrítico del Complemento 3/análisis , Factor H de Complemento/química , Femenino , Glomerulonefritis Membranoproliferativa/genética , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
16.
Clin J Am Soc Nephrol ; 7(3): 417-26, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22223611

RESUMEN

BACKGROUND AND OBJECTIVES: Atypical hemolytic uremic syndrome is a disease associated with mutations in the genes encoding the complement regulators factors H and I. In addition, factor H autoantibodies have been reported in ∼10% of patients with atypical hemolytic uremic syndrome. This study searched for the presence of factor I autoantibodies in atypical hemolytic uremic syndrome. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study screened 175 atypical hemolytic uremic syndrome patients for factor I autoantibodies using ELISA with confirmatory Western blotting. Functional studies using purified immunoglobulin from one patient were subsequently undertaken. RESULTS: Factor I autoantibodies were detected in three patients. In one patient with a high titer of autoantibody, the titer was tracked over time and was found to have no association with disease activity. This study found evidence of an immune complex of antibody and factor I in this patient, but purified IgG, isolated from current serum samples, had only a minor effect on fluid phase and cell surface complement regulation. Genetic analysis of the three patients with factor I autoantibodies revealed that they had two copies of the genes encoding factor H-related proteins 1 and 3 and therefore, did not have a deletion commonly associated with factor H autoantibodies in atypical hemolytic uremic syndrome. Two patients, however, had functionally significant mutations in complement factor H. CONCLUSIONS: These findings reinforce the concept of multiple concurrent risk factors being associated with atypical hemolytic uremic syndrome but question whether autoantibodies per se predispose to atypical hemolytic uremic syndrome.


Asunto(s)
Autoanticuerpos/sangre , Factor I de Complemento/inmunología , Síndrome Hemolítico-Urémico/inmunología , Adulto , Síndrome Hemolítico Urémico Atípico , Western Blotting , Estudios de Casos y Controles , Preescolar , Factor H de Complemento/genética , Análisis Mutacional de ADN , Inglaterra , Ensayo de Inmunoadsorción Enzimática , Femenino , Predisposición Genética a la Enfermedad , Síndrome Hemolítico-Urémico/sangre , Síndrome Hemolítico-Urémico/genética , Humanos , Lactante , Masculino , Mutación , Pronóstico , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo
17.
Immunobiology ; 217(2): 147-57, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21783272

RESUMEN

We have previously demonstrated that mice expressing human complement receptor type 2 (CR2/CD21) during the CD43(+)/CD25(-) late pro-B cell stage of B cell development have marked changes in their subsequent B cell ontogeny. Here, we show that the humoral immune response to the T cell dependent antigen, sheep red blood cells (SRBCs) can be moderately enhanced with the addition of human CR1 (driven by the lambda promoter/enhancer transgene) to endogenous mCR1/CR2 expression on the B cell surface but that hCR1 expression alone (on the mouse CR1/2 deficient background) has no effect on the humoral immune response or general B cell development. Furthermore, expression of hCR1 had no recuperative effect on the markedly altered B cell phenotype noted with premature expression of hCR2 (either in the presence or absence of endogenous mCR1/2). We conclude that hCR1 alone cannot replace the role of CR2 in mice and that the effects of premature hCR2 expression during BCR development are not significantly altered by the addition of hCR1 at that developmental stage or beyond; thus hCR2 signaling in the mouse remains dominant over subsequent input from either hCR1 or endogenous receptors.


Asunto(s)
Linfocitos B/inmunología , Inmunidad Humoral , Receptores de Complemento 3b/inmunología , Animales , Formación de Anticuerpos , Eritrocitos/inmunología , Centro Germinal/inmunología , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Receptores de Complemento 3b/genética , Transducción de Señal/inmunología , Transgenes
18.
BMC Microbiol ; 10: 232, 2010 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-20809975

RESUMEN

BACKGROUND: Poultry meat is one of the most important sources of human campylobacteriosis, an acute bacterial enteritis which is a major problem worldwide. Campylobacter coli and Campylobacter jejuni are the most common Campylobacter species associated with this disease. These pathogens live in the intestinal tract of most avian species and under commercial conditions they spread rapidly to infect a high proportion of the flock, which makes their treatment and prevention very difficult. Bacteriophages (phages) are naturally occurring predators of bacteria with high specificity and also the capacity to evolve to overcome bacterial resistance. Therefore phage therapy is a promising alternative to antibiotics in animal production. This study tested the efficacy of a phage cocktail composed of three phages for the control of poultry infected with C. coli and C. jejuni. Moreover, it evaluated the effectiveness of two routes of phage administration (by oral gavage and in feed) in order to provide additional information regarding their future use in a poultry unit. RESULTS: The results indicate that experimental colonisation of chicks was successful and that the birds showed no signs of disease even at the highest dose of Campylobacter administered. The phage cocktail was able to reduce the titre of both C. coli and C. jejuni in faeces by approximately 2 log10 cfu/g when administered by oral gavage and in feed. This reduction persisted throughout the experimental period and neither pathogen regained their former numbers. The reduction in Campylobacter titre was achieved earlier (2 days post-phage administration) when the phage cocktail was incorporated in the birds' feed. Campylobacter strains resistant to phage infection were recovered from phage-treated chickens at a frequency of 13%. These resistant phenotypes did not exhibit a reduced ability to colonize the chicken guts and did not revert to sensitive types. CONCLUSIONS: Our findings provide further evidence of the efficacy of phage therapy for the control of Campylobacter in poultry. The broad host range of the novel phage cocktail enabled it to target both C. jejuni and C. coli strains. Moreover the reduction of Campylobacter by approximately 2 log10cfu/g, as occurred in our study, could lead to a 30-fold reduction in the incidence of campylobacteriosis associated with consumption of chicken meals (according to mathematical models). To our knowledge this is the first report of phage being administered in feed to Campylobacter-infected chicks and our results show that it lead to an earlier and more sustainable reduction of Campylobacter than administration by oral gavage. Therefore the present study is of extreme importance as it has shown that administering phages to poultry via the food could be successful on a commercial scale.


Asunto(s)
Bacteriófagos/fisiología , Infecciones por Campylobacter/veterinaria , Campylobacter coli/virología , Campylobacter jejuni/virología , Pollos , Enfermedades de las Aves de Corral/prevención & control , Animales , Infecciones por Campylobacter/microbiología , Infecciones por Campylobacter/prevención & control , Campylobacter coli/fisiología , Campylobacter jejuni/fisiología , Femenino , Masculino , Enfermedades de las Aves de Corral/microbiología
20.
Mol Ecol Resour ; 9(3): 784-9, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-21564743

RESUMEN

The orchids in the genus Chiloglottis are pollinated exclusively by sexual deception. Extensive sequencing (> 19.5 kb) of noncoding chloroplast DNA revealed that simple sequence repeats (cpSSRs) were abundant, enabling a set of 41 cpSSR markers to be developed. All markers were polymorphic across the genus. Polymorphism reflected variation at both mononucleotide repeats and indels. For a subset of four taxa with 40 samples each, locus polymorphism varied from 46 to 81%, while the number of haplotypes ranged from seven to 21 per taxon. Extensive differentiation among the taxa was detected. These cpSSRs markers will enable novel insights into the evolution of this unique genus.

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