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BACKGROUND: Ipilimumab, an immune checkpoint inhibitor targeting CTLA-4, prolongs survival in a subset of patients with metastatic melanoma (MM) but can induce immune-related adverse events, including enterocolitis. We hypothesized that baseline gut microbiota could predict ipilimumab anti-tumor response and/or intestinal toxicity. PATIENTS AND METHODS: Twenty-six patients with MM treated with ipilimumab were prospectively enrolled. Fecal microbiota composition was assessed using 16S rRNA gene sequencing at baseline and before each ipilimumab infusion. Patients were further clustered based on microbiota patterns. Peripheral blood lymphocytes immunophenotypes were studied in parallel. RESULTS: A distinct baseline gut microbiota composition was associated with both clinical response and colitis. Compared with patients whose baseline microbiota was driven by Bacteroides (cluster B, n = 10), patients whose baseline microbiota was enriched with Faecalibacterium genus and other Firmicutes (cluster A, n = 12) had longer progression-free survival (P = 0.0039) and overall survival (P = 0.051). Most of the baseline colitis-associated phylotypes were related to Firmicutes (e.g. relatives of Faecalibacterium prausnitzii and Gemmiger formicilis), whereas no colitis-related phylotypes were assigned to Bacteroidetes. A low proportion of peripheral blood regulatory T cells was associated with cluster A, long-term clinical benefit and colitis. Ipilimumab led to a higher inducible T-cell COStimulator induction on CD4+ T cells and to a higher increase in serum CD25 in patients who belonged to Faecalibacterium-driven cluster A. CONCLUSION: Baseline gut microbiota enriched with Faecalibacterium and other Firmicutes is associated with beneficial clinical response to ipilimumab and more frequent occurrence of ipilimumab-induced colitis.
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Antineoplásicos Inmunológicos/uso terapéutico , Colitis/complicaciones , Intestinos/microbiología , Ipilimumab/uso terapéutico , Melanoma/tratamiento farmacológico , Microbiota , Anciano , Colitis/microbiología , Femenino , Humanos , Masculino , Melanoma/complicaciones , Melanoma/microbiología , Melanoma/patología , Metástasis de la Neoplasia , Estudios Prospectivos , ARN Ribosómico 16S/genéticaRESUMEN
Over the last decades, significant advances in the diagnosis and therapeutics have considerably improved success rate from bone marrow transplant in patients suffering from otherwise life-threatening diseases, allowing now for prolonged survival and better quality of life after an allograft. However, infectious diseases remain one of the most serious complication in this population, hence associated with a high morbidity and mortality. Prevention, in particular through vaccination, constitutes a cornerstone of the management of immunocompromised hosts, since this procedure aims to protect them once back to life in community after long periods of hospitalization. If the necessity of vaccinating immunocompromised patients as well as their family is unequivocally recognized among health care workers, some questions remain source of debate. Several famous societies edited guidelines, but those differ from each other and cannot be transposed from a country to another without considering their local epidemiology and implemented vaccination schedule. Moreover, development and availability of new vaccines render recommendations constantly susceptible to adaptations. After exhaustive literature review, this article aims to offer pragmatic answers to the main questions raised by healthcare workers when vaccinating children after a bone marrow transplant. We here review all vaccines available and discuss their modalities of administration considering the timing after transplant, the immunological residual status and the medical history of the child. We also offer clues to optimize vaccination of patients' siblings. In addition to highlight some interrogations about future vaccines formulations, we propose here a vaccination schedule tailored for pediatric bone marrow transplant recipients in Belgium in 2017.
Au cours des dernières années, les progrès faits dans les domaines thérapeutiques et diagnostiques ont permis d'améliorer les performances des traitements par greffes de moelle osseuse, allongeant ainsi significativement l'espérance de vie des patients souffrant de maladies jusqu'alors associées à un sombre pronostic. Cependant, aujourd'hui encore, les infections restent parmi les complications les plus redoutées en termes de morbidité et de mortalité chez ces patients. La prévention et particulièrement la vaccination occupe donc une place primordiale dans la prise en charge de ces hôtes fragiles, visant à les protéger une fois leur retour à la vie en communauté envisagé après de longues périodes d'immunosuppression. Si la nécessité de vacciner les patients transplantés et leur entourage fait l'unanimité au sein des soignants, les modalités de vaccination restent encore sujettes à de maintes interrogations dans la littérature. Plusieurs sociétés réputées font état de recommandations mais celles-ci varient entre elles et ne peuvent être transposées d'un pays à l'autre sans tenir compte de l'épidémiologie locale et du schéma vaccinal préalablement implémenté. Par ailleurs, la mise à disposition constante de nouveaux vaccins nécessite une adaptation perpétuelle des diverses recommandations établies. Sur base d'une revue exhaustive de la littérature, nous tenterons dans cet article d'apporter des réponses pragmatiques aux questions fréquemment soulevées par les soignants en charge des enfants greffés de moelle osseuse. Le document détaille les différents vaccins disponibles, en discute les critères d'administration selon le délai par rapport à la greffe et le statut immunologique du patient et revoit comment optimaliser la vaccination de l'entourage. En plus de souligner certaines interrogations à suivre concernant de nouvelles formulations vaccinales à venir, l'article ci-dessous offre un schéma pratique d'administration des différents vaccins chez les enfants receveurs d'une greffe de moelle en Belgique en 2017.
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OBJECTIVES: Preventing postoperative recurrence after ileocolonic resection (ICR) for Crohn's disease (CD) is challenging. Defining the disturbances of the microbial composition and community structure after ICR and their link with early disease recurrence is crucial. DESIGN: Microbiota composition (fingerprinting and 16S rDNA sequencing) and community structure (correlation networks of bacterial species) were assessed from ileal mucosa sampled in 20 patients undergoing ICR and 6â months later during endoscopy from above (neoterminal ileum) and below (subanastomotic colon) the surgical anastomosis. RESULTS: ICR had a dramatic effect on gut microbial ecosystem. At surgery, CD mucosa harboured a dysbiotic microbiota with high proportions of α/ß Proteobacteria and Bacilli. Six months later, half of the patients had recurrent lesions at ileocolonoscopy and presented higher numbers of Lachnospiraceae. Recurrence of endoscopic lesions was associated with enrichment in Enterococcus durans while patients in remission had increased proportions of Dorea longicatena and Bacteroides plebeius. Structural differences were striking between recurrence and remission microbiota; while the microbiota of patients with CD recurrence exhibited a loose community structure, the microbiota of patients in remission displayed communities that were robustly correlated to each other. Microbiota colonising the neoterminal ileum and subanastomotic colon 6â months after ICR only differed in patients with recurrence. CONCLUSIONS: ICR modifies the gut microbiome. Remission after 6â months was associated with homogenous bacterial distribution around the anastomosis. Community structure and bacterial networks highlight target species, including Faecalibacterium prausnitzii and Ruminococcus gnavus, which may allow precise modulations of the overall microbial ecosystem towards remission pattern.
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Colon/cirugía , Enfermedad de Crohn/microbiología , Enfermedad de Crohn/cirugía , Microbioma Gastrointestinal , Íleon/cirugía , Lactobacillus johnsonii/metabolismo , Biopsia , Colon/patología , Enfermedad de Crohn/patología , Método Doble Ciego , Disbiosis/prevención & control , Estudios de Seguimiento , Humanos , Íleon/patología , Mucosa Intestinal/microbiología , Recurrencia , Inducción de RemisiónRESUMEN
OBJECTIVE: There is substantial inter-individual diversity in the susceptibility of alcoholics to liver injury. Alterations of intestinal microbiota (IM) have been reported in alcoholic liver disease (ALD), but the extent to which they are merely a consequence or a cause is unknown. We aimed to demonstrate that a specific dysbiosis contributes to the development of alcoholic hepatitis (AH). DESIGN: We humanised germ-free and conventional mice using human IM transplant from alcoholic patients with or without AH. The consequences on alcohol-fed recipient mice were studied. RESULTS: A specific dysbiosis was associated with ALD severity in patients. Mice harbouring the IM from a patient with severe AH (sAH) developed more severe liver inflammation with an increased number of liver T lymphocyte subsets and Natural Killer T (NKT) lymphocytes, higher liver necrosis, greater intestinal permeability and higher translocation of bacteria than mice harbouring the IM from an alcoholic patient without AH (noAH). Similarly, CD45+ lymphocyte subsets were increased in visceral adipose tissue, and CD4(+)T and NKT lymphocytes in mesenteric lymph nodes. The IM associated with sAH and noAH could be distinguished by differences in bacterial abundance and composition. Key deleterious species were associated with sAH while the Faecalibacterium genus was associated with noAH. Ursodeoxycholic acid was more abundant in faeces from noAH mice. Additionally, in conventional mice humanised with the IM from an sAH patient, a second subsequent transfer of IM from an noAH patient improved alcohol-induced liver lesions. CONCLUSIONS: Individual susceptibility to ALD is substantially driven by IM. It may, therefore, be possible to prevent and manage ALD by IM manipulation.
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Disbiosis/complicaciones , Microbioma Gastrointestinal , Hepatopatías Alcohólicas/microbiología , Animales , Susceptibilidad a Enfermedades/microbiología , Femenino , Humanos , Ratones , Ratones Endogámicos C57BLRESUMEN
Whole exome sequencing (WES) has greatly facilitated the identification of causal mutations for diverse human genetic disorders. We applied WES as a molecular diagnostic tool to identify disease-causing genes in consanguineous families in Qatar. Seventeen consanguineous families with diverse disorders were recruited. Initial mutation screening of known genes related to the clinical diagnoses did not reveal the causative mutations. Using WES approach, we identified the definitive disease-causing mutations in four families: (i) a novel nonsense homozygous (c.1034C>G) in PHKG2 causing glycogen storage disease type 9C (GSD9C) in a male with initial diagnosis of GSD3; (ii) a novel homozygous 1-bp deletion (c.915del) in NSUN2 in a male proband with Noonan-like syndrome; (iii) a homozygous SNV (c.1598C>G) in exon 11 of IDUA causing Hurler syndrome in a female proband with unknown clinical diagnosis; (iv) a de novo known splicing mutation (c.1645+1G>A) in PHEX in a female proband with initial diagnosis of autosomal recessive hypophosphatemic rickets. Applying WES as a diagnostic tool led to the unambiguous identification of disease-causing mutations in phenotypically complex disorders or correction of the initial clinical diagnosis in Ë25% of our cases.
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Consanguinidad , Enfermedad/genética , Exoma/genética , Predisposición Genética a la Enfermedad , Análisis de Secuencia de ADN , Familia , Femenino , Humanos , Masculino , Padres , Linaje , QatarRESUMEN
Varicella is a frequent viral disease, with a substantial medical and societal impact. For many years, various industrialized countries have adopted an universal mass vaccination against varicella, using a one-dose schedule. In these countries, the global incidence of varicella has decreased by about 90%. A significant reduction in hospitalizations, outpatient visits and medical costs due to varicella has also been observed. Recently, a 2-dose schedule has demonstrated an efficacy of about 98%, as well as herd immunity.
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Vacuna contra la Varicela/administración & dosificación , Varicela/prevención & control , Varicela/epidemiología , Vacuna contra la Varicela/efectos adversos , Política de Salud , Herpesvirus Humano 3/inmunología , Humanos , Inmunidad Colectiva , Vacunación/normasRESUMEN
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS or SACS) is an early onset neurodegenerative disease with high prevalence (carrier frequency 1/22) in the Charlevoix-Saguenay-Lac-Saint-Jean (CSLSJ) region of Quebec. We previously mapped the gene responsible for ARSACS to chromosome 13q11 and identified two ancestral haplotypes. Here we report the cloning of this gene, SACS, which encodes the protein sacsin. The ORF of SACS is 11,487 bp and is encoded by a single gigantic exon spanning 12,794 bp. This exon is the largest to be identified in any vertebrate organism. The ORF is conserved in human and mouse. The putative protein contains three large segments with sequence similarity to each other and to the predicted protein of an Arabidopsis thaliana ORF. The presence of heat-shock domains suggests a function for sacsin in chaperone-mediated protein folding. SACS is expressed in a variety of tissues, including the central nervous system. We identified two SACSmutations in ARSACS families that lead to protein truncation, consistent with haplotype analysis.
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Ataxia/genética , Cromosomas Humanos Par 13 , Proteínas de Choque Térmico/genética , Mutación , Sistemas de Lectura Abierta , Degeneraciones Espinocerebelosas/genética , Secuencia de Aminoácidos , Animales , Arabidopsis/genética , Secuencia de Bases , Mapeo Cromosómico , Exones , Proteínas de Choque Térmico/química , Humanos , Desequilibrio de Ligamiento , Ratones , Datos de Secuencia Molecular , Prevalencia , Quebec/epidemiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia , Homología de Secuencia de AminoácidoRESUMEN
INTRODUCTION: Hyposmia is a common cause of functional complaint in patients with nasal polyposis. The aim of the current study was to report the olfactory functional results after sinus surgery. MATERIALS AND METHODS: A systematic review of the scientific literature was achieved in the Pubmed database. RESULTS: Overall, 10 series published between 1989 and 2013, involving 959 patients, were selected. The surgery for nasal polyposis, adjuvant medical treatment, may allow olfactory improvement. The results are even better than surgery is as wide as possible and the evolutionary stage is low.
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Pólipos Nasales/fisiopatología , Pólipos Nasales/cirugía , Trastornos del Olfato/cirugía , Olfato/fisiología , Humanos , Pólipos Nasales/complicaciones , Trastornos del Olfato/etiología , Procedimientos Quirúrgicos Otorrinolaringológicos/estadística & datos numéricos , Resultado del TratamientoRESUMEN
BACKGROUND: Cancers of uppers aero-digestives tracts represent, infrequency, the 5th cancer in the French population. Most of them (about 70%) are diagnosed at an advanced stage (stage III or IV) while they are associated with a poor prognosis (only 40% five year survival). The objective of our study was to analyze the care pathway of patients with cancers of uppers aero-digestives tracts in order to target efforts to improve the survival of these patients. METHODS: It was a descriptive and retrospective study, on medical files, on the health care pathway of patients with cancers of uppers aero-digestives tracts cared in the Head and Neck surgery department of Val de Grâce in Paris and Percy in Clamart between January 2004 and December 2006. The patients were adults with squamous cell carcinoma of uppers aero-digestives tracts. RESULTS: One hundred thirty-eight files of patients were analyzed. Fifty-five percent of patients were diagnosed at an advanced stage. On average patients have waited two months and twenty-one days before consulting a doctor for the first time. The time interval between the specialist consultation and the start of treatment was on average 7 weeks. The overall 5-year survival rate was 61%. CONCLUSION: Squamous cell carcinoma of uppers aero-digestives tracts remains serious and has a poor diagnosis, even in a population with a high social-cultural level. The long time interval before the first consultation may be reduced by improving health education among the general practitioner (primary and secondary prevention), and by establishing health care public campaigns. This would allow earlier diagnosis, more conservative therapeutic opportunities and therefore a better prognosis.
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Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/terapia , Neoplasias de Oído, Nariz y Garganta/terapia , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/patología , Vías Clínicas , Supervivencia sin Enfermedad , Diagnóstico Precoz , Intervención Médica Temprana , Femenino , Francia , Humanos , Metástasis Linfática/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias de Oído, Nariz y Garganta/diagnóstico , Neoplasias de Oído, Nariz y Garganta/mortalidad , Neoplasias de Oído, Nariz y Garganta/patología , Pronóstico , Estudios RetrospectivosRESUMEN
AIMS/HYPOTHESIS: Evidence suggests that bacterial components in blood could play an early role in events leading to diabetes. To test this hypothesis, we studied the capacity of a broadly specific bacterial marker (16S rDNA) to predict the onset of diabetes and obesity in a general population. METHODS: Data from an Epidemiological Study on the Insulin Resistance Syndrome (D.E.S.I.R.) is a longitudinal study with the primary aim of describing the history of the metabolic syndrome. The 16S rDNA concentration was measured in blood at baseline and its relationship with incident diabetes and obesity over 9 years of follow-up was assessed. In addition, in a nested case-control study in which participants later developed diabetes, bacterial phylotypes present in blood were identified by pyrosequencing of the overall 16S rDNA gene content. RESULTS: We analysed 3,280 participants without diabetes or obesity at baseline. The 16S rDNA concentration was higher in those destined to have diabetes. No difference was observed regarding obesity. However, the 16S rDNA concentration was higher in those who had abdominal adiposity at the end of follow-up. The adjusted OR (95% CIs) for incident diabetes and for abdominal adiposity were 1.35 (1.11, 1.60), p = 0.002 and 1.18 (1.03, 1.34), p = 0.01, respectively. Moreover, pyrosequencing analyses showed that participants destined to have diabetes and the controls shared a core blood microbiota, mostly composed of the Proteobacteria phylum (85-90%). CONCLUSIONS/INTERPRETATION: 16S rDNA was shown to be an independent marker of the risk of diabetes. These findings are evidence for the concept that tissue bacteria are involved in the onset of diabetes in humans.
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Biomarcadores/sangre , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/microbiología , Síndrome Metabólico/sangre , Metagenoma , ARN Ribosómico 16S/sangre , Adulto , Anciano , Bacterias/clasificación , Bacterias/aislamiento & purificación , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/epidemiología , Femenino , Francia , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Obesidad/sangre , Obesidad Abdominal/sangre , Obesidad Abdominal/epidemiologíaRESUMEN
Carotid cavernous fistula (CCF) is an abnormal communication between the cavernous sinus and the carotid arterial system. The authors reported the clinical presentation and therapeutic procedure of two cases. The physician has to be aware of this diagnosis when a patient is referred for a posttraumatic exophthalmia. The medical behaviour is multidisciplinary (ENT, ophthalmologist, radiologist and neurosurgeon). The imaging of choice is the angiography but angio-MRI and angio-CT can help to confirm the diagnosis. The endovascular embolization is the treatment of choice. It presents an acceptable risk of complication and a low risk of failure. In this paper the authors report 2 posttraumatic CCF cases treated with success by endovascular embolization.
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Traumatismos por Explosión , Fístula del Seno Cavernoso de la Carótida , Embolización Terapéutica/métodos , Exoftalmia/etiología , Angiografía/métodos , Traumatismos por Explosión/diagnóstico , Traumatismos por Explosión/diagnóstico por imagen , Traumatismos por Explosión/terapia , Bombas (Dispositivos Explosivos) , Fístula del Seno Cavernoso de la Carótida/diagnóstico , Fístula del Seno Cavernoso de la Carótida/diagnóstico por imagen , Fístula del Seno Cavernoso de la Carótida/etiología , Fístula del Seno Cavernoso de la Carótida/terapia , Humanos , Angiografía por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Grupo de Atención al Paciente , Factores de Riesgo , Tomografía Computarizada por Rayos X/métodosRESUMEN
OBJECTIVES: Studies of acute gastroenteritis (AGE) are hampered by the lack of routine diagnostic methods with good sensitivity and specificity. Molecular methods are increasingly used for clinical purposes, but the clinical significance of a positive result remains a challenge. In this study we aimed to compare results of routine diagnostic methods and molecular methods in symptomatic children and asymptomatic controls. METHODS: Patients presenting to the pediatric emergency departments of two university hospitals in Brussels with AGE were recruited prospectively from May 2015 to October 2016; asymptomatic controls were recruited from the same hospitals. Stool analyses were performed for all participants for common pathogenic bacteria (culture), virus (immunochromatography) and parasites (microscopy). Stools were also analysed with the Luminex Gastrointestinal Pathogen Panel, a multiplex-PCR for common enteropathogens. RESULTS: Stools from 178 patients and 165 controls were analysed. An enteropathogen was detected in 62.4% (111/178) of cases when combining the two methods (56.2% (100/178) by Luminex, 42.7% (76/178) with routine methods) and 29.1% (48/165) of controls (24.2% (40/165) by Luminex and 10.3% (17/165) by routine methods). Some pathogens were detected more often with Luminex than with routine methods, such as Salmonella (16.3% (29/178) with Luminex and 3.9% (7/178) with routine method, p < 0.05), whereas others identified by culture methods, such as Campylobacter, Shigella, Yersinia, were missed by Luminex. CONCLUSIONS: Molecular tools seem attractive methods, providing high positivity and a rapid turn-around time for the diagnosis of AGE. However, high rates of positivity in both cases and controls highlight the difficulty in interpreting results. Pathogens missed by Luminex but detected by culture methods raise more questions about the true clinical interest of the technique for our patients.
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Pruebas Diagnósticas de Rutina/métodos , Gastroenteritis/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Preescolar , Diarrea/diagnóstico , Diarrea/microbiología , Diarrea/parasitología , Diarrea/virología , Heces/microbiología , Heces/parasitología , Heces/virología , Femenino , Gastroenteritis/microbiología , Gastroenteritis/parasitología , Gastroenteritis/virología , Humanos , Masculino , Técnicas Microbiológicas , Reacción en Cadena de la Polimerasa Multiplex , Sensibilidad y EspecificidadRESUMEN
Mucolipidosis (ML) II (I-cell disease) is a lysosomal storage disorder caused by a deficiency of UDP-N-acetylglucosamine:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase. MLII is an autosomal recessive disease with a carrier rate estimated at 1/39 in Saguenay-Lac-Saint-Jean (SLSJ) (Quebec, Canada), which is the highest frequency documented worldwide. To identify the causing mutation, we sequenced GNPTAB exons in 27 parents of 16 MLII-deceased children from the SLSJ region as obligatory and potential carriers. We also performed a genealogical reconstruction for each parent to evaluate consanguinity levels and genetic contribution of ancestors. Our goal was to identify which parameters could explain the high MLII frequency observed in the SLSJ population. A single mutation (c.3503_3504delTC) was found in all obligatory carriers. In addition, 11 apparent polymorphisms were identified. The mutation was not detected in genomic DNA of 50 unrelated controls. Genealogical data show six founders (three couples) with a higher probability of having introduced the mutation in the population. The frequency of the mutation was increased as a consequence of this founder effect and of the resulting population structure. We suggest that c.3503_3504delTC is the allele causing MLII in the SLSJ population, and its high carrier rate is most likely explained by a founder effect.
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Efecto Fundador , Mucolipidosis/enzimología , Mucolipidosis/genética , Mutación/genética , Transferasas (Grupos de Otros Fosfatos Sustitutos)/genética , Población Blanca/genética , Canadá , Estudios de Casos y Controles , Consanguinidad , Análisis Mutacional de ADN , Genealogía y Heráldica , Geografía , HumanosRESUMEN
The epithelium of the intestinal mucosa and the gut-associated lymphoid tissues (GALT) constitute an essential physical and immunological barrier against pathogens. In order to study the specificities of the GALT transcriptome in pigs, we compared the transcriptome profiles of jejunal and ileal Peyer's patches (PPs), mesenteric lymph nodes (MLNs) and peripheral blood (PB) of four male piglets by RNA-Seq. We identified 1,103 differentially expressed (DE) genes between ileal PPs (IPPs) and jejunal PPs (JPPs), and six times more DE genes between PPs and MLNs. The master regulator genes FOXP3, GATA3, STAT4, TBX21 and RORC were less expressed in IPPs compared to JPPs, whereas the transcription factor BCL6 was found more expressed in IPPs. In comparison between IPPs and JPPs, our analyses revealed predominant differential expression related to the differentiation of T cells into Th1, Th2, Th17 and iTreg in JPPs. Our results were consistent with previous reports regarding a higher T/B cells ratio in JPPs compared to IPPs. We found antisense transcription for respectively 24%, 22% and 14% of the transcripts detected in MLNs, PPs and PB, and significant positive correlations between PB and GALT transcriptomes. Allele-specific expression analyses revealed both shared and tissue-specific cis-genetic control of gene expression.
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Íleon/metabolismo , Yeyuno/metabolismo , Tejido Linfoide/metabolismo , Ganglios Linfáticos Agregados/metabolismo , Transcriptoma/genética , Animales , Linfocitos B/citología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Femenino , Íleon/inmunología , Yeyuno/inmunología , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Tejido Linfoide/inmunología , Masculino , Mesenterio/inmunología , Mesenterio/metabolismo , Ganglios Linfáticos Agregados/inmunología , Porcinos , Linfocitos T/citología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Transcriptoma/inmunología , Secuenciación del Exoma/métodosRESUMEN
In multidrug-resistant (MDR) derivatives of the mouse lymphoid tumor P388, the emergence of MDR is associated with overexpression and transcriptional activation of the mdr3 gene, either in the absence of (P388/VCR-10) or concomitant with (P388/ADM-2) gene amplification. In both instances, Northern (RNA) blotting analyses have suggested the presence of altered mdr3 transcripts in these cells, possibly originating from novel transcription initiation sites. The mechanisms underlying mdr3 overexpression in these cells have been investigated. In P388/VCR-10 cells, Southern blotting analyses together with genomic DNA cloning and nucleotide sequencing have demonstrated the presence of an intact mouse mammary tumor virus (MMTV) within the boundaries of intron 1 of mdr3. cDNA cloning and nucleotide sequencing indicated that this integration event results in the synthesis and overexpression of a hybrid MMTV-mdr3 mRNA which initiates within the U3 region of the 5' long terminal repeat (LTR) of the provirus. Consequently, this mRNA lacks the normal exon 1 of mdr3 but contains (i) MMTV LTR-derived sequences at its 5' end, (ii) a novel mdr3 exon, mapping within the boundaries of intron 1 downstream of the MMTV integration site and generated by alternative splicing, and (iii) an otherwise intact 3' portion of mdr3 starting at exon 2. A similar type of analysis of P388/ADM-2 cells revealed that mdr3 overexpression in these cells is associated with the integration of an intracisternal A particle (IAP) within an L1Md repetitive element, immediately upstream of mdr3. The IAP insertion results in the overexpression of hybrid IAP-mdr3 mRNA transcripts that initiate within the 3' LTR of the IAP and which contain IAP LTR-derived sequences at the 5' end spliced 14 nucleotides upstream of the normal exon 1 of mdr3. Taken together, these results indicate that independent retroviral insertions were the initial mutagenic event responsible for mdr3 overexpression and survival during drug selection of these cell lines. Amplification of the rearranged and activated mdr3 gene copy occurred during further selection for high-level drug resistance in P388/ADM-2 cells.
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Resistencia a Medicamentos/genética , Regulación Neoplásica de la Expresión Génica , Leucemia P388/genética , Virus del Tumor Mamario del Ratón/genética , Animales , Secuencia de Bases , Mapeo Cromosómico , Clonación Molecular , ADN de Neoplasias/genética , Elementos de Facilitación Genéticos , Reordenamiento Génico , Lisogenia/genética , Ratones , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Provirus/genética , ARN Mensajero/genética , ARN Neoplásico/genética , Activación Transcripcional , Células Tumorales Cultivadas/efectos de los fármacosRESUMEN
The human intestinal microbiota is composed of approximately 100,000 billion microorganisms with the average total number of different commensal bacterial species estimated at over 500 per individual. The human intestinal microbiota can be considered as an organ within another, which co-evolved with its host to achieve a symbiotic relationship leading to physiological homeostasis. The host provides an environment enriched in nutrients and the microbiota provides essential functions. Dysbiosis of the intestinal microbiota (changes in bacterial composition) has been associated with local dysfunctions of the gastrointestinal tract, such as inflammatory bowel disease or irritable bowel syndrome but also with obesity and metabolic diseases. However, a better understanding of the human intestinal ecosystem is still needed to understand the exact role of the microbiota in health and disease. Most intestinal bacteria are anaerobic and therefore, for the large majority, impossible to culture at present. Consequently, their function cannot be inferred from data on their composition. Today, with the help of a metagenomic approach, the bacterial genomic content of an ecosystem and the associated functions can be directly accessed from the environment without culture.
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Disbiosis/etiología , Microbioma Gastrointestinal/fisiología , Tracto Gastrointestinal/microbiología , Interacciones Huésped-Patógeno/fisiología , Inflamación/etiología , Disbiosis/microbiología , Humanos , Enfermedades Inflamatorias del Intestino/microbiología , Enfermedades Metabólicas/microbiologíaRESUMEN
We review the evidence that strongly suggests a role of the intestinal microbiota in the onset and perpetuation of inflammatory bowel disease (IBD). Experimental studies consisted of suppressing micro-organisms from the microbiota (using germ-free or gnotoxenic animals or antibiotics), introducing new micro-organisms or microbial components (e.g. probiotics, CpG-DNA) or selectively increasing some endogenous bacteria (e.g. using prebiotics). Intervention studies were performed in patients or animal models of spontaneous or chemically-induced colitis. Information was also obtained from observational studies that described the composition of the faecal and mucosal microbiota at various stages of the disease process and in controls. Many have used culture-independent techniques that identify bacteria based on the nucleic acid sequence of ribosomal RNA molecules. Microbiota in patients with IBD seem to be characterized by high concentrations of bacteria in contact with the mucosa, instability, the presence of high numbers of unusual bacteria and sometimes a reduction in the biodiversity. Studies searching for a generalized or localized dysbiosis in IBD are discussed, as well as those trying to identify bacterial molecules and receptors, which may be implicated in triggering the inflammatory process.
Asunto(s)
Infecciones Bacterianas , Enfermedades Inflamatorias del Intestino/microbiología , Humanos , Probióticos/uso terapéuticoRESUMEN
The "Bacterial Meningitis Score" (BMS) has been designed to identify children at low (BMS = 0) or high (BMS > or = 2) risk of bacterial meningitis (M). Its calculation is simple; it is based on 5 different items: Gram stain, seizure at or before presentation, peripheral white blood cell count (WBC), cerebrospinal fluid (CSF) WBC and CSF protein concentration. As of today, it has been validated in one single study in the United States. The purpose of this study is to evaluate the BMS performance in children hospitalized for M over a 5 years period. The medical records of 277 patients diagnosed with M, aged 29 days to 15 years and hospitalized in the Department of Pediatrics of the CHR Citadelle Hospital in Liège between 1999 and 2003 were analysed. Among the 277 hospitalised cases, there were 29 bacterial (10,5%) and 248 viral (89,5%) M. For patients whose BMS < 2, we found 100% of viral M. For those with BMS > or = 2, 59,3% had a bacterial M and 40,7% had a viral M. 23% of the children with BMS < 2 were treated with antibiotics; 17% of children with BMS = 2 were not been treated on admission. The BMS is an easily applicable method that could allow reduce the unnecessary use of antibiotics.
Asunto(s)
Meningitis Bacterianas/diagnóstico , Meningitis Viral/diagnóstico , Adolescente , Niño , Preescolar , Diagnóstico Diferencial , Humanos , Lactante , Recién Nacido , Estudios Retrospectivos , Índice de Severidad de la EnfermedadRESUMEN
In independently derived drug-resistant sublines of the mouse lymphoid tumor P388, multidrug resistance is associated with the exclusive overexpression of the mdr3 gene. In P388/VCR cells, mdr3 overexpression occurs in the absence of gene amplification, while in P388/ADM-2 cells overexpression is associated with mdr3 gene amplification. The mechanism underlying mdr3 overexpression in these cells was investigated. Measurement of the rate of transcription by nuclear "run-on" assays showed that increased mdr3 expression in P388/VCR cells was caused by transcriptional activation of the gene. Analysis of the 5' end of mdr3 mRNA transcripts by primer extension indicated that in P388/VCR cells, these mRNAs extended approximately 200 nucleotides upstream exon 2, about 60 nucleotides longer than their counterparts expressed in normal tissues from the known transcription start site of the gene (TS1). Northern blotting experiments using discrete exon and intron probes derived from the 5' end of the gene near TS1, together with ribonuclease protection using a complementary RNA probe from the same region, demonstrated that transcriptional activation in P388/VCR cells occurred from a novel transcription start site named TS3, located either upstream of TS1 or within intron 1 at a site immediately upstream a novel exon. In P388/ADM-2 cells, Northern blotting and ribonuclease protection identified overexpressed mdr3 mRNAs initiating near TS1 and a large partially spliced mdr3 mRNA species initiating upstream of TS1 at a novel initiation site designated TS2. Therefore, mdr3 overexpression in independently derived multidrug-resistant isolates of P388 cells is associated with the appearance of novel transcription start sites in the gene and novel sequences at the 5' end of the overexpressed mRNAs.