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1.
J Clin Pharm Ther ; 45(4): 767-773, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32415738

RESUMEN

WHAT IS KNOWN AND OBJECTIVE: We evaluated the effect of the proportion of time maintained within the target international normalized ratio (INR) postoperatively in hospitalized patients who underwent On-X mechanical heart valve replacement on warfarin therapy after discharge. METHODS: Inclusion was patients who were ≥18 years, received warfarin for a minimum of 10 days without any interruptions during hospitalization and followed by the anticoagulation service (ACS) clinic after discharge between June 2006 and June 2016. Patients were excluded if they had incomplete medical records, INR goal changes, known as warfarin resistance, transferred to another facility or expired during the study. The patients were divided into 3 groups according to the proportion of time maintained within therapeutic INR range (TTR) from day 4 to 10 of warfarin initiation (low: <30%, moderate: ≥30% to <70%, and high: ≥70%). The number of days needed to reach target INR for 2 consecutive measurements after discharge and the number of ACS visits was compared among the groups. RESULTS AND DISCUSSION: Among 539 postoperative patients, 273 were included. The baseline demographics were similar among the 3 groups. The mean time needed to reach target INR for 2 consecutive measurements was 68.6 ± 106.1 days. The low group required time needed to reach target INR for 2 consecutive measurements of 94.0 ± 140.9 days compared with 44.8 ± 57.1 days in the high group (P = .007). Additionally, the low group had more ACS visits than the high group (low, 6.6 ± 5.2 vs high, 4.6 ± 3.9; P = .025). Patient compliance affected the time needed to reach target INR for 2 consecutive measurements (compliant, 42.36 ± 58.5 days vs non-compliant, 132.0 ± 157.1 days, P < .001). WHAT IS NEW AND CONCLUSION: The study implicated that high postoperative TTR would reduce the time to require post-discharge target INR and the number of ACS visits.


Asunto(s)
Anticoagulantes/uso terapéutico , Implantación de Prótesis de Válvulas Cardíacas , Warfarina/uso terapéutico , Adulto , Cuidados Posteriores , Anciano , Femenino , Humanos , Relación Normalizada Internacional , Masculino , Persona de Mediana Edad , Cooperación del Paciente , Alta del Paciente , Estudios Retrospectivos , Factores de Tiempo
2.
Biol Pharm Bull ; 42(4): 594-600, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30930418

RESUMEN

Sex-related incidence and outcomes were reported in various cancers, including colorectal cancer. 5-Fluorouracil (5-FU) is widely used as an essential chemotherapeutic agent for colorectal cancer. However, sex-based differences in 5-FU toxicity have yet to be reported in human cancer cell lines and xenograft mouse models to date. Here, we investigated, for the first time, sex-based differences in 5-FU toxicity using human colon cancer cell lines, xenograft mouse models, and Korean patients' data. Female-derived colon cancer cell lines exhibited greater 5-FU-induced cytotoxicity than male-derived colon cancer cell lines. We established two xenograft mouse models: one with a male-derived human colon cancer cell line injected into male mice (a male-xenograft model) and another involving a female-derived human colon cancer cell line injected into female mice (a female xenograft model). Treatment with 5-FU inhibited tumor growth and led to hematological toxicity in a female xenograft model more potently than in a male xenograft model. We analyzed the data obtained from Korean patients with colorectal cancer to examine sex differences in adverse drug reactions caused by 5-FU. Korean female patients with colorectal cancer who received 5-FU chemotherapy experienced more frequent adverse drug reactions including alopecia and leukopenia than male patients. Taken together, we demonstrated that female may be associated with increased risk of toxicity to 5-FU treatment in colorectal cancer based on in vitro and in vivo investigations and clinical data analysis. Our study suggests sex as an important clinical factor, which predicts induction of toxicity related to 5-FU treatment.


Asunto(s)
Antimetabolitos Antineoplásicos/efectos adversos , Neoplasias Colorrectales/tratamiento farmacológico , Fluorouracilo/efectos adversos , Anciano , Animales , Pueblo Asiatico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Neoplasias Colorrectales/patología , Femenino , Humanos , Masculino , Ratones Endogámicos BALB C , Ratones Desnudos , Persona de Mediana Edad , Caracteres Sexuales , Carga Tumoral
3.
Clin Nephrol ; 88(9): 148-155, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28699888

RESUMEN

AIMS: Measured glomerular filtration rate (mGFR) is often used to identify augmented renal clearance (ARC). However, in the clinical setting, estimated GFR (eGFR) is obtained more quickly and inexpensively. We aimed to determine whether eGFR can identify ARC by evaluating the correlation between the eGFR and vancomycin trough level (VTL). MATERIALS AND METHODS: We retrospectively reviewed the records of patients aged ≤ 18 years who underwent vancomycin therapeutic drug monitoring at our tertiary hospital from July 2009 to June 2014. VTL, serum creatinine concentration, eGFR, and clinical factors affecting VTL were analyzed. RESULTS: Of 101 patients, 76 (75.25%) had a subtherapeutic VTL. Patient age (p = 0.006), the daily vancomycin dose (p = 0.041) and dosing interval (p = 0.006), and eGFR (p < 0.001) affected the VTL. Multivariate analysis showed a significant relationship between eGFR and VTL (adjusted R2, 0.812; p < 0.001). An increased eGFR (odds ratio, 1.002; 95% confidence interval, 1.001 - 1.003; p = 0.001) was a risk factor for a subtherapeutic vancomycin level. The cutoff eGFR value predicting a subtherapeutic vancomycin level was 110.51 mL/min/1.73m2 (area under the curve, 0.753). CONCLUSIONS: The eGFR correlates with the VTL, and the eGFR cutoff value can predict a subtherapeutic vancomycin level. eGFR is a reliable and efficient alternative to mGFR for identifying ARC.
.


Asunto(s)
Tasa de Filtración Glomerular , Riñón/metabolismo , Vancomicina/farmacocinética , Adolescente , Niño , Preescolar , Creatinina/sangre , Enfermedad Crítica , Monitoreo de Drogas , Femenino , Humanos , Masculino , Estudios Retrospectivos
4.
BMC Pediatr ; 16: 113, 2016 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-27465214

RESUMEN

BACKGROUND: Nutritional support is critical for preterm infants in the neonatal intensive care unit (NICU). A multidisciplinary nutritional support team (NST) that focuses on providing optimal and individualized nutrition care could be helpful. We conducted a thorough evaluation of clinical and nutritional outcomes in a tertiary NICU following the implementation of an NST. METHODS: This study used a retrospective approach with historical comparisons. Preterm neonates < 30 weeks gestational age or weighing < 1250 g were enrolled. Clinical and nutritional outcomes were compared before and after the establishment of the NST. Medical records were reviewed, and clinical and nutritional outcomes were compared between the two groups. RESULTS: In total, 107 patients from the pre-NST period and 122 patients from the post-NST period were included. The cumulative energy delivery during the first week of life improved during the post-NST period (350.17 vs. 408.62 kcal/kg, p < 0.001). The cumulative protein and lipid deliveries also significantly increased. The time required to reach full enteric feedings decreased during the post-NST period (6.4 ± 5.8 vs. 4.7 ± 5.1 days, p = 0.016). Changes of Z-score in weight from admission to discharge exhibited more favorable results in the post-NST period (-1.13 ± 0.99 vs.-0.91 ± 0.74, p = 0.055), and the length of ICU stay significantly decreased in the post-NST period (81.7 ± 36.6 vs. 72.2 ± 32.9 days, p = 0.040). CONCLUSIONS: NST intervention in the NICU resulted in significant improvements in the provision of nutrition to preterm infants in the first week of life. There were also favorable clinical outcomes, such as increased weight gain and reduced length of ICU stay. Evaluable data remain sparse in the NICU setting with premature neonatal populations; therefore, the successful outcomes identified in this study may provide support for NST practices.


Asunto(s)
Fenómenos Fisiológicos Nutricionales del Lactante , Cuidado Intensivo Neonatal/métodos , Estado Nutricional , Apoyo Nutricional/métodos , Grupo de Atención al Paciente , Femenino , Humanos , Recién Nacido , Recien Nacido Prematuro , Unidades de Cuidado Intensivo Neonatal/organización & administración , Cuidado Intensivo Neonatal/organización & administración , Modelos Lineales , Masculino , Evaluación de Procesos y Resultados en Atención de Salud , Evaluación de Programas y Proyectos de Salud , Estudios Retrospectivos
5.
Support Care Cancer ; 23(7): 1969-77, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25500718

RESUMEN

PURPOSE: Weekly or tri-weekly docetaxel treatment mandates the use of dexamethasone to prevent toxicity. However, the adverse effects of prophylactic steroid use are often overlooked. We investigated the incidence of corticosteroid-associated adverse effects during docetaxel therapy, focusing on hyperglycemia and infection as well as the identification of possible risk factors. METHODS: This study was conducted through retrospective chart review of 632 patients who started docetaxel-based chemotherapy between July 2011 and June 2012 at Seoul National University Hospital. Hyperglycemia was defined as more than two random glucose levels >200 mg/dL. All documented episodes of infection that required treatment with antibiotics were regarded as infectious episodes. RESULTS: The incidences of hyperglycemia in overall patients and in patients without previous diabetes mellitus were 13.7 and 10.9%, respectively. Infectious episodes greater than grade 2 and grade 3 developed in 29.6 and 19.9% of patients, respectively. Multivariable logistic regression analysis showed that body mass index and previous diabetes mellitus were independent risk factors for hyperglycemia, whereas corticosteroid dose was not. Treatment duration and frequency of high blood glucose levels over 200 mg/dL were independent risk factors for infection. CONCLUSIONS: Due to the significant difference in patient and treatment characteristics, we could not obtain meaningful comparisons between weekly and tri-weekly docetaxel administration regimens. This study suggests that adverse effects associated with prophylactic steroid use need to be recognized and optimally managed during docetaxel therapy.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Dexametasona/administración & dosificación , Dexametasona/efectos adversos , Hiperglucemia/inducido químicamente , Taxoides/administración & dosificación , Taxoides/efectos adversos , Adulto , Anciano , Antineoplásicos Hormonales/administración & dosificación , Antineoplásicos Hormonales/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias de la Mama/tratamiento farmacológico , Estudios de Cohortes , Docetaxel , Esquema de Medicación , Femenino , Humanos , Infecciones/inducido químicamente , Neoplasias Pulmonares/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Adulto Joven
6.
Mol Microbiol ; 77(4): 1021-38, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20572934

RESUMEN

Fimbriae are adhesive organelles known to enable pathogens to colonize animal tissue, but little is known of their function in mutualistic symbioses. Photorhabdus colonization of Heterorhabditis bacteriophora nematodes is essential for the pair's insect pathogenic lifestyle. Maternal nematodes acquire Photorhabdus symbionts as a persistent intestinal biofilm prior to transmission to infective juvenile (IJ) stage offspring developing inside the maternal body. Screening 8000 Photorhabdus mutants for defects in IJ colonization revealed that a single fimbrial locus, named mad for maternal adhesion defective, is essential. The mad genes encode a novel usher/chaperone assembled fimbria regulated by an ON/OFF invertible promoter switch. Adherent Photorhabdus cells in maternal nematode intestines had the switch ON opposite to the OFF orientation of most other cells. A ΔmadA mutant failed to adhere to maternal intestines and be transmitted to the IJs. Mad fimbriae were detected on TT01 phase ON cells but not on ΔmadA phase ON cells. Also required for transmission is madJ, predicted to encode a transcriptional activator related to GrlA. Expression of madA-K or madIJK restored the ability of madJ mutant to adhere. The Mad fimbriae were not required for insect pathogenesis, indicating the specialized function of Mad fimbriae for symbiosis.


Asunto(s)
Adhesión Bacteriana , Proteínas Fimbrias/metabolismo , Photorhabdus/fisiología , Rhabditoidea/microbiología , Simbiosis , Animales , Biopelículas/crecimiento & desarrollo , Proteínas Fimbrias/genética , Tracto Gastrointestinal/microbiología , Eliminación de Gen , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos , Sitios Genéticos , Familia de Multigenes , Operón , Photorhabdus/genética , Regiones Promotoras Genéticas , Rhabditoidea/crecimiento & desarrollo
7.
J Clin Med ; 9(2)2020 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-32046138

RESUMEN

Adalimumab is used at 40-mg dose to treat systemic inflammatory diseases. Given the impact of adverse drug reactions (ADRs), which particularly result in the discontinuation of adalimumab therapy in female patients, this study examined whether sex affects the frequency and type of ADRs induced by adalimumab. In this study, the prescription records and laboratory data of patients aged ≥19 years who had been admitted to the Seoul National University Hospital (SNUH) and prescribed adalimumab were analyzed using an electronic medical record database. The analysis revealed that female patients more frequently experienced adalimumab-induced ADRs compared with male patients (63.2% vs. 52.2%). The incidence of ADRs was significantly higher in female patients with ankylosing spondylitis or rheumatoid arthritis than in male patients with similar conditions (81.5% vs. 60.7% or 64.4% vs. 50.0%, respectively). The median body weight (BW) was lower in female patients than in male patients (54.0 vs. 66.0 kg). Moreover, the incidence of ADRs in patients with a BW of <54.0 kg (i.e., the median female BW) was higher than for those with a BW of ≥54.0 kg, in both males and females. Our results suggested that the predominance of ADRs induced by adalimumab in females was because of their relatively lower BW. This suggests the importance of BW as a determining factor in sex disparity of ADR occurrences.

8.
Toxicol Res ; 35(4): 319-330, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31636843

RESUMEN

Adverse drug reactions (ADRs) constitute key factors in determining successful medication therapy in clinical situations. Integrative analysis of electronic medical record (EMR) data and use of proper analytical tools are requisite to conduct retrospective surveillance of clinical decisions on medications. Thus, we suggest that electronic medical recording and human genetic databases are considered together in future directions of pharmacovigilance. We analyzed EMR-based ADR studies indexed on PubMed during the period from 2005 to 2017 and retrospectively acquired 1161 (29.6%) articles describing drug-induced adverse reactions (e.g., liver, kidney, nervous system, immune system, and inflammatory responses). Of them, only 102 (8.79%) articles contained useful information to detect or predict ADRs in the context of clinical medication alerts. Since insufficiency of EMR datasets and their improper analyses may provide false warnings on clinical decision, efforts should be made to overcome possible problems on data-mining, analysis, statistics, and standardization. Thus, we address the characteristics and limitations on retrospective EMR database studies in hospital settings. Since gene expression and genetic variations among individuals impact ADRs, pharmacokinetics, and pharmacodynamics, appropriate paths for pharmacovigilance may be optimized using suitable databases available in public domain (e.g., genome-wide association studies (GWAS), non-coding RNAs, microRNAs, proteomics, and genetic variations), novel targets, and biomarkers. These efforts with new validated biomarker analyses would be of help to repurpose clinical and translational research infrastructure and ultimately future personalized therapy considering ADRs.

9.
Appl Environ Microbiol ; 74(8): 2275-87, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18281425

RESUMEN

Many animals and plants have symbiotic relationships with beneficial bacteria. Experimentally tractable models are necessary to understand the processes involved in the selective transmission of symbiotic bacteria. One such model is the transmission of the insect-pathogenic bacterial symbionts Photorhabdus spp. by Heterorhabditis bacteriophora infective juvenile (IJ)-stage nematodes. By observing egg-laying behavior and IJ development, it was determined that IJs develop exclusively via intrauterine hatching and matricide (i.e., endotokia matricida). By transiently exposing nematodes to fluorescently labeled symbionts, it was determined that symbionts infect the maternal intestine as a biofilm and then invade and breach the rectal gland epithelium, becoming available to the IJ offspring developing in the pseudocoelom. Cell- and stage-specific infection occurs again in the pre-IJ pharyngeal intestinal valve cells, which helps symbionts to persist as IJs develop and move to a new host. Synchronous with nematode development are changes in symbiont and host behavior (e.g., adherence versus invasion). Thus, Photorhabdus symbionts are maternally transmitted by an elaborate infectious process involving multiple selective steps in order to achieve symbiont-specific transmission.


Asunto(s)
Photorhabdus/crecimiento & desarrollo , Rhabditoidea/microbiología , Animales , Biopelículas/crecimiento & desarrollo , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Mucosa Intestinal/microbiología , Intestinos/microbiología , Microscopía Electrónica de Transmisión , Faringe/microbiología , Rhabditoidea/ultraestructura , Simbiosis
10.
Springerplus ; 5(1): 1435, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27652011

RESUMEN

In order to improve the reporting of adverse drug reactions (ADRs) as part of the routine practice at the pediatric outpatient department (OPD), we modified our ADR reporting strategy into one that facilitates the reporting process by means of a multi-disciplinary approach. In this study, we retrospectively reviewed ADR records during the period from March to September 2014 when we changed our reporting process as a part of institutional quality assurance (QA) activity. Yearly differences in the number and composition of ADRs were compared, and the descriptive analyses were done for cases reported from OPD during the QA activity in terms of the suspected drugs, type, causality, and severity of ADRs. There were 1211 pediatric ADR reports including 520 cases with underlying hemato-oncologic diseases during the period of 2014. Among the 691 non-oncologic cases, 76 were reported from the OPD, which was a significant increase (347 %) from the 17 cases reported during the previous year. Further analyses of these 76 cases revealed that the caregivers (47.4 %) initiated about half of the reports, the most frequently affected organ was the skin (32.9 %), and the most frequent suspected drugs were anticonvulsants (14.5 %). In contrast to the in-ward system, moderate cases were more frequent (51.3 %) than mild ones. In conclusion, this study provides a profile of pediatric ADRs in the OPD, which were largely under-reported during the usual clinical practice. A multi-disciplinary approach would improve spontaneous ADR reporting at the pediatric OPD.

11.
World J Transplant ; 6(2): 403-10, 2016 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-27358786

RESUMEN

AIM: To analyze the association between plasma bilirubin levels and veno-occlusive disease (VOD) in non-adult patients undergoing hematopoietic stem cell transplantation (HSCT) during cyclosporine therapy. METHODS: A total of 123 patients taking cyclosporine were evaluated using an electronic medical system at the Seoul National University Children's Hospital from the years 2004 through 2011. Patients were grouped by age and analyzed for incidence and type of adverse drug reactions (ADRs) including VOD. RESULTS: The HSCT patients were divided into three age groups: G#1 ≥ 18; 9 ≤ G#2 ≤ 17; and G#3 ≤ 8 years of age). The majority of transplant donor types were cord blood transplantations. Most prevalent ADRs represented acute graft-vs-host disease (aGVHD) and VOD. Although the incidences of aGVHD did not vary among the groups, the higher frequency ratios of VOD in G#3 suggested that an age of 8 or younger is a risk factor for developing VOD in HSCT patients. After cyclosporine therapy, the trough plasma concentrations of cyclosporine were lower in G#3 than in G#1, indicative of its increased clearance. Moreover, in G#3 only, a maximal total bilirubin level (BILmax) of ≥ 1.4 mg/dL correlated with VOD incidence after cyclosporine therapy. CONCLUSION: HSCT patients 8 years of age or younger are more at risk for developing VOD, diagnosed as hyperbilirubinemia, tender hepatomegaly, and ascites/weight gain after cyclosporine therapy, which may be represented by a criterion of plasma BILmax being ≥ 1.4 mg/dL, suggestive of more sensitive VOD indication in this age group.

12.
Cancer Chemother Pharmacol ; 74(3): 653-7, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25096796

RESUMEN

PURPOSE: Bortezomib-induced peripheral neuropathy (BIPN) is a significant neurotoxicity, requiring dose reduction or the delay of treatment. In a multicentre trial including 97 % Caucasians and 3 % Asians, BIPN was shown to occur less frequently in cases in which bortezomib was administered subcutaneously. Considering the different pharmacokinetics between Caucasians and Asians, we analysed BIPN according to the administration route, specifically in Korean myeloma patients. METHODS: We surveyed the prescribed anticonvulsants for the treatment of BIPN and analysed the data after stratifying the results by the cumulative dose of bortezomib. Exclusion criteria were as follows: treated with <2 doses of bortezomib, change in the administration route during the treatment, or receiving anticonvulsants for other reasons prior to bortezomib administration. RESULTS: A total of 101 patients were enrolled; 60 were treated with bortezomib and dexamethasone, and 37 were treated with bortezomib, melphalan, and prednisolone. The median number of treatment courses was four for each regimens. The median exposure to bortezomib for all patients was 19 mg/m(2). Progression-free survival (PFS) and overall survival rates were not statistically different between the groups. There was no difference in the proportion of patients requiring medical treatment (p = 0.388). After stratifying the results, BIPN developed less frequently when bortezomib was administered subcutaneously rather than intravenously in patients receiving more than 23.4 mg/m(2) of bortezomib (p < 0.05). CONCLUSION: Since the responses were potent regardless of administration route, the subcutaneous injection of bortezomib should be considered in Asian myeloma patients who are expected to achieve a longer PFS with bortezomib.


Asunto(s)
Antineoplásicos/administración & dosificación , Antineoplásicos/efectos adversos , Ácidos Borónicos/administración & dosificación , Ácidos Borónicos/efectos adversos , Mieloma Múltiple/tratamiento farmacológico , Enfermedades del Sistema Nervioso Periférico/inducido químicamente , Pirazinas/administración & dosificación , Pirazinas/efectos adversos , Anciano , Anticonvulsivantes/uso terapéutico , Antineoplásicos Hormonales/administración & dosificación , Antineoplásicos Hormonales/efectos adversos , Antineoplásicos Hormonales/uso terapéutico , Pueblo Asiatico , Bortezomib , Femenino , Humanos , Inyecciones Subcutáneas , Masculino , Persona de Mediana Edad , Mieloma Múltiple/mortalidad , Enfermedades del Sistema Nervioso Periférico/tratamiento farmacológico , Estudios Retrospectivos , Resultado del Tratamiento
13.
PLoS One ; 8(7): e69618, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23874975

RESUMEN

Heterorhabditis bacteriophora are entomopathogenic nematodes that have evolved a mutualism with Photorhabdus luminescens bacteria to function as highly virulent insect pathogens. The nematode provides a safe harbor for intestinal symbionts in soil and delivers the symbiotic bacteria into the insect blood. The symbiont provides virulence and toxins, metabolites essential for nematode reproduction, and antibiotic preservation of the insect cadaver. Approximately half of the 21,250 putative protein coding genes identified in the 77 Mbp high quality draft H. bacteriophora genome sequence were novel proteins of unknown function lacking homologs in Caenorhabditis elegans or any other sequenced organisms. Similarly, 317 of the 603 predicted secreted proteins are novel with unknown function in addition to 19 putative peptidases, 9 peptidase inhibitors and 7 C-type lectins that may function in interactions with insect hosts or bacterial symbionts. The 134 proteins contained mariner transposase domains, of which there are none in C. elegans, suggesting an invasion and expansion of mariner transposons in H. bacteriophora. Fewer Kyoto Encyclopedia of Genes and Genomes Orthologies in almost all metabolic categories were detected in the genome compared with 9 other sequenced nematode genomes, which may reflect dependence on the symbiont or insect host for these functions. The H. bacteriophora genome sequence will greatly facilitate genetics, genomics and evolutionary studies to gain fundamental knowledge of nematode parasitism and mutualism. It also elevates the utility of H. bacteriophora as a bridge species between vertebrate parasitic nematodes and the C. elegans model.


Asunto(s)
Genoma/genética , Photorhabdus , Proteínas/genética , Rhabditoidea/genética , Rhabditoidea/microbiología , Simbiosis/genética , Animales , ADN Complementario/genética , Biblioteca de Genes , Secuenciación de Nucleótidos de Alto Rendimiento , Redes y Vías Metabólicas/genética , Repeticiones de Microsatélite/genética , Filogenia , Proteínas/metabolismo , Interferencia de ARN , Especificidad de la Especie
14.
Science ; 337(6090): 88-93, 2012 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-22767929

RESUMEN

Microbial populations stochastically generate variants with strikingly different properties, such as virulence or avirulence and antibiotic tolerance or sensitivity. Photorhabdus luminescens bacteria have a variable life history in which they alternate between pathogens to a wide variety of insects and mutualists to their specific host nematodes. Here, we show that the P. luminescens pathogenic variant (P form) switches to a smaller-cell variant (M form) to initiate mutualism in host nematode intestines. A stochastic promoter inversion causes the switch between the two distinct forms. M-form cells are much smaller (one-seventh the volume), slower growing, and less bioluminescent than P-form cells; they are also avirulent and produce fewer secondary metabolites. Observations of form switching by individual cells in nematodes revealed that the M form persisted in maternal nematode intestines, were the first cells to colonize infective juvenile (IJ) offspring, and then switched to P form in the IJ intestine, which armed these nematodes for the next cycle of insect infection.


Asunto(s)
Mariposas Nocturnas/microbiología , Photorhabdus/genética , Photorhabdus/patogenicidad , Regiones Promotoras Genéticas , Rhabditoidea/microbiología , Inversión de Secuencia , Simbiosis , Animales , Proteínas Fimbrias/genética , Regulación Bacteriana de la Expresión Génica , Genoma Bacteriano , Intestinos/microbiología , Mutación , Fenotipo , Photorhabdus/citología , Photorhabdus/crecimiento & desarrollo , Virulencia/genética
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