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1.
Br J Surg ; 107(11): 1429-1439, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32492186

RESUMEN

BACKGROUND: Sentinel node navigation surgery reduces the extent of gastric and lymph node dissection, and may improve quality of life. The benefit and harm of laparoscopic sentinel node navigation surgery (LSNNS) for early gastric cancer is unknown. The SENORITA (SEntinel Node ORIented Tailored Approach) trial investigated the pathological and surgical outcomes of LSNNS compared with laparoscopic standard gastrectomy (LSG) with lymph node dissection. METHODS: The SENORITA trial was an investigator-initiated, open-label, parallel-assigned, non-inferiority, multicentre RCT conducted in Korea. The primary endpoint was 3-year disease-free survival. The secondary endpoints, morbidity and mortality within 30 days of surgery, are reported in the present study. RESULTS: A total of 580 patients were randomized to LSG (292) or LSNNS (288). Surgery was undertaken in 527 patients (LSG 269, LSNNS 258). LSNNS could be performed according to the protocol in 245 of 258 patients, and a sentinel node basin was detected in 237 (96·7 per cent) Stomach-preserving surgery was carried out in 210 of 258 patients (81·4 per cent). Postoperative complications occurred in 51 patients in the LSG group (19·0 per cent) and 40 (15·5 per cent) in the LSNNS group (P = 0·294). Complications with a Clavien-Dindo grade of III or higher occurred in 16 (5·9 per cent) and 13 (5·0 per cent) patients in the LSG and LSNNS groups respectively (P = 0·647). CONCLUSION: The rate and severity of complications following LSNNS for early gastric cancer are comparable to those after LSG with lymph node dissection. Registration number: NCT01804998 ( http://www.clinicaltrials.gov).


ANTECEDENTES: La cirugía de navegación del ganglio centinela (sentinel node navigation surgery, SNNS) reduce la extensión de la resección gástrica y ganglionar, y puede mejorar la calidad de vida. Se desconoce el beneficio y el daño de la cirugía de navegación del ganglio centinela por vía laparoscópica (laparoscopic sentinel node navigation surgery, LSNNS) para el cáncer gástrico precoz. El ensayo clínico SENORITA investigó los resultados patológicos y quirúrgicos de LSNNS en comparación con la gastrectomía laparoscópica estándar (laparoscopic gastrectomy, LSG) con disección ganglionar (lymph node dissection, LND). MÉTODOS: El ensayo SENORITA fue un ensayo multicéntrico aleatorizado y controlado, iniciado por investigadores, abierto, con asignación a grupos paralelos y de no inferioridad llevado a cabo en Corea. El resultado primario fue la supervivencia libre de enfermedad a los 3 años. En el presente estudio, se describen los resultados secundarios correspondientes a morbilidad y mortalidad a los 30 días del postoperatorio. RESULTADOS: Un total de 580 pacientes fueron aleatorizados a LG (n = 292) o LSNNS (n = 288). La cirugía se realizó en 527 pacientes (LG 269, LSNNS 258). LSNNS pudo ser realizada de acuerdo con el protocolo en 245 de 258 pacientes y en 237 de 245 pacientes (96,7%) se detectó un ganglio centinela. La cirugía con preservación del estómago se realizó en 210 de 258 pacientes (81,4%). Las complicaciones postoperatorias se presentaron en 51 pacientes del grupo LSG (19,0%) y en 40 pacientes (15,5%) del grupo LSNNS (P = 0,294). Las complicaciones grado III o mayor de Clavien-Dindo se detectaron en 16 (5,9%) y 13 pacientes (5,0%) de los grupos LSG y LSNNS, respectivamente (P = 0,647). CONCLUSIÓN: El porcentaje y la gravedad de las complicaciones tras LSNNS para cancer gástrico precoz son comparables a la LSG con LND.


Asunto(s)
Adenocarcinoma/cirugía , Gastrectomía/métodos , Laparoscopía/métodos , Escisión del Ganglio Linfático/métodos , Ganglio Linfático Centinela/cirugía , Neoplasias Gástricas/cirugía , Adenocarcinoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Análisis de Intención de Tratar , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Complicaciones Posoperatorias/epidemiología , Ganglio Linfático Centinela/patología , Neoplasias Gástricas/patología , Resultado del Tratamiento
2.
BJOG ; 124(2): 262-268, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27362908

RESUMEN

OBJECTIVE: To determine if higher-volume, fixed-dose administration of vasopressin further reduces blood loss at the time of minimally invasive myomectomy. DESIGN: Randomised multicentre clinical trial. SETTING: Tertiary-care academic centres in the USA. POPULATION: Women undergoing conventional laparoscopic or robot-assisted laparoscopic myomectomy. METHODS: All participants received the same 10-unit (U) dose of vasopressin, but were randomly assigned to one of two groups: (i) received 200 ml of diluted vasopressin solution (20 U in 400 ml normal saline), and (ii) received 30 ml of concentrated vasopressin solution (20 U in 60 ml normal saline). MAIN OUTCOME MEASURES: The primary study outcome was estimated blood loss; the study was powered to detect a 100-ml difference. RESULTS: A total of 152 women were randomised; 76 patients in each group. Baseline demographics were similar between groups. The primary outcome of intraoperative blood loss was not significantly different, as measured by three parameters: surgeon estimate (mean estimated blood loss 178 ± 265 ml and 198 ± 232 ml, dilute and concentrated groups respectively, P = 0.65), suction canister-calculated blood loss, or change in haematocrit levels. There were no vasopressin-related adverse events. CONCLUSION: Both dilute and concentrated vasopressin solutions that use the same drug dosing demonstrate comparable safety and tolerability when administered for minimally invasive myomectomy; however, higher volume administration of vasopressin does not reduce blood loss. TWEETABLE ABSTRACT: This randomised trial failed to show benefit of high-volume dilute vasopression.


Asunto(s)
Pérdida de Sangre Quirúrgica/prevención & control , Hemostasis Quirúrgica/métodos , Hemostáticos/administración & dosificación , Laparoscopía/métodos , Miomectomía Uterina/efectos adversos , Vasopresinas/administración & dosificación , Adulto , Femenino , Hemostáticos/química , Humanos , Leiomioma/cirugía , Persona de Mediana Edad , Miomectomía Uterina/métodos , Neoplasias Uterinas/cirugía , Vasopresinas/química
3.
J Appl Microbiol ; 123(3): 570-581, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28383815

RESUMEN

Escherichia coli is classified as a rod-shaped, Gram-negative bacterium in the family Enterobacteriaceae. The bacterium mainly inhabits the lower intestinal tract of warm-blooded animals, including humans, and is often discharged into the environment through faeces or wastewater effluent. The presence of E. coli in environmental waters has long been considered as an indicator of recent faecal pollution. However, numerous recent studies have reported that some specific strains of E. coli can survive for long periods of time, and potentially reproduce, in extraintestinal environments. This indicates that E. coli can be integrated into indigenous microbial communities in the environment. This naturalization phenomenon calls into question the reliability of E. coli as a faecal indicator bacterium (FIB). Recently, many studies reported that E. coli populations in the environment are affected by ambient environmental conditions affecting their long-term survival. Large-scale studies of population genetics revealed the diversity and complexity of E. coli strains in various environments, which are affected by multiple environmental factors. This review examines the current knowledge on the ecology of E. coli strains in various environments with regard to its role as a FIB and as a naturalized member of indigenous microbial communities. Special emphasis is given on the growth of pathogenic E. coli in the environment, and the population genetics of environmental members of the genus Escherichia. The impact of environmental E. coli on water quality and public health is also discussed.


Asunto(s)
Escherichia coli/aislamiento & purificación , Agua Dulce/microbiología , Animales , Escherichia coli/clasificación , Escherichia coli/genética , Escherichia coli/fisiología , Infecciones por Escherichia coli/microbiología , Heces/microbiología , Humanos , Salud Pública , Contaminación del Agua
4.
Clin Radiol ; 71(3): 250-7, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26747329

RESUMEN

AIM: To fully characterise the magnetic resonance imaging (MRI) traits of rectal cancers in a large sample of patients, each experiencing pathological complete remission (pCR) after neoadjuvant concurrent chemoradiation therapy (CCRT). MATERIALS AND METHODS: A total of 120 patients (77 male, 43 female; median age, 59.5 years; range, 32-81 years) with rectal cancers in CCRT-induced pCR states who underwent pre- and post-CCRT MRI and eventual surgery between July, 2005 and September, 2014 were retrospectively reviewed. In most (n=100), diffusion-weighted imaging was also performed. Tumour volume, tumour regression grade (TRG), T-stage, mesorectal fascia (MRF) status, and T2 signal intensity (T2-SI) were analysed. Paired t-test and McNemar's test were applied for statistical comparisons. RESULTS: Tumour volume declined sharply after CCRT (pre-CCRT, 21.5 ± 22.4 cm(3); post-CCRT, 6.6 ± 8.4 cm(3); p<0.001). TRG distribution was as follows: G1 (clinical CR), 3; G2, 38; G3, 78; G4, 1; and G5 (marked progression), 0. Downstaging of T-stage (34%,16/47) and MRF status (19.7%,13/66) did occur; but on post-CCRT MRI, 25.8% (31/120) remained at T3 ≥ 5 mm or T4 stage, and 44.2% (53/120) were MRF-positive. A majority (88.3%, 106/120) of patients displayed intermediate T2-SI prior to CCRT. Most converted to dark T2-SI after CCRT, with 12.5% (15/120) unchanged. On post-CCRT MRI, 11% (11/100) of patients showed diffusion restriction. CONCLUSION: MRI findings in CCRT-induced pCR-status rectal cancers were highly variable. Tumour volume and T2-SI mostly decreased; however, such lesions occasionally presented with unexpected atypical features, such as large residual volume and/or intermediate T2-SI.


Asunto(s)
Quimioradioterapia , Imagen por Resonancia Magnética/métodos , Neoplasias del Recto/patología , Neoplasias del Recto/terapia , Adulto , Anciano , Anciano de 80 o más Años , Imagen de Difusión por Resonancia Magnética , Femenino , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Clasificación del Tumor , Estadificación de Neoplasias , Inducción de Remisión , Resultado del Tratamiento , Carga Tumoral
5.
Br J Cancer ; 106(1): 53-60, 2012 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-22068817

RESUMEN

BACKGROUND: This study aims to evaluate the effectiveness of adenosine triphosphate-based chemotherapy response assay (ATP-CRA)-guided neoadjuvant chemotherapy for increasing resectability in patients with unresectable colorectal liver metastasis. PATIENTS AND METHODS: Patients were randomised into two groups: Group A was treated by conventional chemotherapy regimen and Group B was treated by chemotherapy regimen according to the ATP-CRA. Three chemotherapeutic agents (5-fluorouracil, oxaliplatin and irinotecan) were tested by ATP-CRA and more sensitive agents were selected. Either FOLFOX or FOLFIRI was administered. Between Group A and B, treatment response and resectability were compared. RESULTS: Between November 2008 and October 2010, a total 63 patients were randomised to Group A (N=32) or Group B (N=31). FOLFOX was more preferred in Group A than in Group B (26 out of 32 (81.3%) vs 20 out of 31 (64.5%)). Group B showed better treatment response than Group A (48.4% vs 21.9%, P=0.027). The resectability of hepatic lesion was higher in Group B (35.5% vs 12.5%, P=0.032). Mean duration from chemotherapy onset to the time of liver resection was 11 cycles (range 4-12) in Group A and 8 cycles (range 8-16) in Group B. CONCLUSION: This study showed that tailored-chemotherapy based on ATP-CRA could improve the treatment response and resectability in initially unresectable colorectal liver metastasis.


Asunto(s)
Adenosina Trifosfato/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Colorrectales/patología , Neoplasias Hepáticas/tratamiento farmacológico , Adulto , Anciano , Neoplasias Colorrectales/tratamiento farmacológico , Terapia Combinada , Estudios de Factibilidad , Femenino , Humanos , Neoplasias Hepáticas/secundario , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
6.
Br J Surg ; 99(1): 133-6, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22038650

RESUMEN

BACKGROUND: The aim of this study was to identify the benefits of robotic transanal specimen extraction (RTSE) compared with minilaparotomy specimen extraction (MSE). METHODS: Patients who underwent totally robotic surgery with curative intent for treatment of adenocarcinoma of the rectum below 12 cm from the anal verge were selected from the authors' database. Patients were divided into RTSE and MSE groups according to the method of specimen delivery. Clinicopathological features and perioperative surgical outcomes were compared between the two groups. RESULTS: There were 53 patients in the RTSE group and 66 in the MSE group. No differences were observed in overall complications. Postoperative recovery was faster in the RTSE group in terms of resumption of a soft diet (mean(s.d.) 3·5(1·5) versus 4·6(1·7) days; P < 0·001) and length of hospital stay (9·0(4·8) versus 11·3(5·3) days; P = 0·016). Pain scores on a visual analogue scale were significantly lower in the RTSE group than in the MSE group from day 2 to day 5 after surgery (P = 0·021 to P < 0·001). CONCLUSION: RTSE in robotic rectal cancer surgery was associated with less pain and a faster recovery than MSE.


Asunto(s)
Canal Anal , Procedimientos Quirúrgicos del Sistema Digestivo/instrumentación , Neoplasias del Recto/cirugía , Robótica , Manejo de Especímenes/métodos , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Resultado del Tratamiento
12.
Rheumatology (Oxford) ; 48(1): 45-8, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19056796

RESUMEN

OBJECTIVE: MMP is a key enzyme in the degradation of extracellular matrices, and its expression plays important roles in inflammatory diseases. Cordycepin (3'-deoxyadenosine), a bioactive compound of Cordyceps militaris, has been shown to exhibit many pharmacological activities, such as anti-cancer, anti-inflammatory and anti-infection activities. In this study, we aimed at the inhibitory effect of cordycepin on IL-1beta-induced MMP-1 and MMP-3 expression as well as the molecular basis using RA synovial fibroblasts (RASFs). METHODS: RASFs were isolated from synovial tissue obtained from 12 patients with RA and cultured in monolayer. Expression of MMP-1 and MMP-3 was evaluated using western blotting and real-time PCR. Chemokines were analysed by ELISA. The phosphorylation of mitogen-activated protein kinase was measured by western blotting. Electrophoretic mobility shift assay was performed to evaluate binding activities of DNA to nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1). RESULTS: Cordycepin inhibited IL-1beta-induced MMP-1 and MMP-3 expressions in RASFs in a dose-dependent manner. Among various chemokines [such as monocyte chemoattractant protein-1 (MCP-1), GRO-alpha, regulated upon activation, normal T-cell expressed and presumably secreted (RANTES) and epithelial neutrophil activating peptide 78 (ENA-78)], cordycepin specifically blocked IL-1beta-induced ENA-78 production in RASF. Moreover, cordycepin significantly inhibited IL-1beta-induced p38/JNK and AP-1 activation, but not extracellular signal-regulated kinase (ERK) and NF-kappaB activation. CONCLUSIONS: Cordycepin is a potent inhibitor of IL-1beta-induced chemokine production and MMP expression and strongly blocks the p38/JNK/AP-1 signalling pathway in RASFs.


Asunto(s)
Antirreumáticos/farmacología , Artritis Reumatoide/enzimología , Desoxiadenosinas/farmacología , Interleucina-1beta/antagonistas & inhibidores , Metaloproteinasa 1 de la Matriz/biosíntesis , Metaloproteinasa 3 de la Matriz/biosíntesis , Artritis Reumatoide/inmunología , Artritis Reumatoide/patología , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Quimiocinas/biosíntesis , Proteínas de Unión al ADN/metabolismo , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/métodos , Fibroblastos/efectos de los fármacos , Fibroblastos/enzimología , Fibroblastos/patología , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Humanos , Interleucina-1beta/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Metaloproteinasa 1 de la Matriz/genética , Metaloproteinasa 3 de la Matriz/genética , FN-kappa B/metabolismo , Membrana Sinovial/efectos de los fármacos , Membrana Sinovial/enzimología , Membrana Sinovial/patología , Factor de Transcripción AP-1/metabolismo , Regulación hacia Arriba/efectos de los fármacos
13.
Science ; 283(5403): 845-8, 1999 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-9933168

RESUMEN

Stem cell homing and repopulation are not well understood. The chemokine stromal cell-derived factor-1 (SDF-1) and its receptor CXCR4 were found to be critical for murine bone marrow engraftment by human severe combined immunodeficient (SCID) repopulating stem cells. Treatment of human cells with antibodies to CXCR4 prevented engraftment. In vitro CXCR4-dependent migration to SDF-1 of CD34+CD38-/low cells correlated with in vivo engraftment and stem cell function. Stem cell factor and interleukin-6 induced CXCR4 expression on CD34+ cells, which potentiated migration to SDF-1 and engraftment in primary and secondary transplanted mice. Thus, up-regulation of CXCR4 expression may be useful for improving engraftment of repopulating stem cells in clinical transplantation.


Asunto(s)
Antígenos CD , Quimiocinas CXC/fisiología , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/fisiología , Receptores CXCR4/fisiología , ADP-Ribosil Ciclasa , ADP-Ribosil Ciclasa 1 , Animales , Anticuerpos , Antígenos CD34/análisis , Antígenos CD34/inmunología , Antígenos de Diferenciación/análisis , Quimiocina CXCL12 , Quimiocinas CXC/farmacología , Quimiotaxis , Ensayo de Unidades Formadoras de Colonias , Sangre Fetal , Movilización de Célula Madre Hematopoyética , Humanos , Interleucina-6/farmacología , Glicoproteínas de Membrana , Ratones , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , NAD+ Nucleosidasa/análisis , Receptores CXCR4/biosíntesis , Receptores CXCR4/inmunología , Factor de Células Madre/farmacología , Acetato de Tetradecanoilforbol/farmacología , Regulación hacia Arriba
14.
Water Sci Technol ; 59(11): 2205-11, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19494460

RESUMEN

Membrane-based treatment technologies have been introduced as a promising tool for the removal of water-borne pathogens. To ensure successful application of membrane processes, the integrity of the membrane system should be maintained. Related with evaluation of the membrane integrity, USEPA guidance recommends pressure-based membrane integrity (MIT). Based on the bubble point theory, the ability of detecting smallest integrity breakage during the MIT is defined as "Resolution". However, the response to remarkably small breach demands significantly high initial test pressure of the pressure decay test. In this study, the surface tension of the test liquid was controlled to improve the resolution without increasing the corresponding test pressure. Three common chemicals were chosen to control the solution surface tension. It is concluded that 0.1 M of the citric acid can decrease the initial test pressure significantly for the same pore size. Subsequently, the improvement of the resolution with controlled surface tension was confirmed by the results of pressure decay test and marker test.


Asunto(s)
Ensayo de Materiales/métodos , Membranas Artificiales , Tensión Superficial , Purificación del Agua/métodos , Ácido Cítrico , Etanol , Presión
15.
Sci Rep ; 9(1): 13494, 2019 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-31530865

RESUMEN

Despite extensive studies suggesting increased susceptibility to HIV during the secretory phase of the menstrual cycle, the molecular mechanisms involved remain unclear. Our goal was to analyze transcriptomes of the endocervix and ectocervix during the proliferative and secretory phases using RNA sequencing to explore potential molecular signatures of susceptibility to HIV. We identified 202 differentially expressed genes (DEGs) between the proliferative and secretory phases of the cycle in the endocervix (adjusted p < 0.05). The biofunctions and pathways analysis of DEGs revealed that cellular assembly and epithelial barrier function in the proliferative phase and inflammatory response/cellular movement in the secretory phase were among the top biofunctions and pathways. The gene set enrichment analysis of ranked DEGs (score = log fold change/p value) in the endocervix and ectocervix revealed that (i) unstimulated/not activated immune cells gene sets positively correlated with the proliferative phase and negatively correlated with the secretory phase in both tissues, (ii) IFNγ and IFNα response gene sets positively correlated with the proliferative phase in the ectocervix, (iii) HIV restrictive Wnt/ß-catenin signaling pathway negatively correlated with the secretory phase in the endocervix. Our data show menstrual cycle phase-associated changes in both endocervix and ectocervix, which may modulate susceptibility to HIV.


Asunto(s)
Cuello del Útero/metabolismo , Fase Folicular/genética , Perfilación de la Expresión Génica , Fase Luteínica/genética , Transcriptoma , Biología Computacional/métodos , Endometrio/metabolismo , Femenino , Ontología de Genes , Redes Reguladoras de Genes , Humanos , Transducción de Señal
16.
J Clin Invest ; 104(9): 1199-211, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10545519

RESUMEN

The chemokine SDF-1 plays a central role in the repopulation of the bone marrow (BM) by circulating CD34(+) progenitors, but the mechanisms of its action remain obscure. To extravasate to target tissue, a blood-borne cell must arrest firmly on vascular endothelium. Murine hematopoietic progenitors were recently shown in vivo to roll along BM microvessels that display selectins and integrins. We now show that SDF-1 is constitutively expressed by human BM endothelium. In vitro, human CD34(+) cells establish efficient rolling on P-selectin, E-selectin, and the CD44 ligand hyaluronic acid under physiological shear flow. ICAM-1 alone did not tether CD34(+) cells under flow, but, in the presence of surface-bound SDF-1, CD34(+) progenitors rolling on endothelial selectin rapidly developed firm adhesion to the endothelial surface, mediated by an interaction between ICAM-1 and its integrin ligand, which coimmobilized with SDF-1. Human CD34(+) cells accumulated efficiently on TNF-activated human umbilical cord endothelial cells in the absence of SDF-1, but they required immobilized SDF-1 to develop firm integrin-mediated adhesion and spreading. In the absence of selectins, SDF-1 also promoted VLA-4-mediated, Gi protein-dependent tethering and firm adhesion to VCAM-1 under shear flow. To our knowledge, this is the first demonstration that SDF-1 expressed on vascular endothelium is crucial for translating rolling adhesion of CD34(+) progenitors into firm adhesion by increasing the adhesiveness of the integrins VLA-4 and LFA-1 to their respective endothelial ligands, VCAM-1 and ICAM-1.


Asunto(s)
Antígenos CD34/metabolismo , Médula Ósea/metabolismo , Quimiocinas CXC/fisiología , Endotelio Vascular/metabolismo , Células Madre Hematopoyéticas/metabolismo , Integrinas/metabolismo , Adhesión Celular , Quimiocina CXCL12 , Selectina E/metabolismo , Sangre Fetal/metabolismo , Citometría de Flujo , Humanos , Receptores de Hialuranos/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Selectina-P/metabolismo , Estrés Mecánico , Linfocitos T/metabolismo , Molécula 1 de Adhesión Celular Vascular/metabolismo
17.
Mol Endocrinol ; 5(11): 1677-86, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1779970

RESUMEN

Rat insulin-like growth factor-I (IGF-I) mRNAs with different 5'-untranslated region/prepeptide coding sequences result from transcription initiation in one of two leader exons. While not altering the mature IGF-I coding sequence, these different leaders potentially encode two distinct IGF-I prepeptides, one of 48 amino acids (exon 1) and one of 32 amino acids (exon 2). Within exon 1, transcription initiation is dispersed (i.e. occurs over a approximately 350-basepair region), while within exon 2, it is highly localized. A fourth exon 1 start site, residing only approximately 30 basepairs from its 3' end, is suggested on the basis of RNase protection assays; its use would produce an mRNA encoding a third distinct IGF-I leader peptide of 22 amino acids. We have determined that during postnatal development, and as a result of insulinopenic diabetes and fasting, choice of transcription start sites within exon 1 in the liver is coordinately regulated, i.e. use of all start sites increased during development and decreased in the two catabolic states. Transcription initiation at the single major site within exon 2 was also reduced in diabetes and fasting. Insulin replacement therapy and refeeding restored the levels of all transcripts coordinately. During postnatal development, however, transcripts initiating within exon 2 exhibited a different developmental profile than did exon 1 transcripts, increasing especially at the onset of GH-dependent linear growth. In liver, therefore, negative regulation of exon 1 and exon 2 transcription start site usage occurs in catabolic states, while in development, differential regulation of exon 1 and exon 2 transcription start sites occurs.


Asunto(s)
Diabetes Mellitus Experimental/genética , Exones , Ayuno/fisiología , Regulación de la Expresión Génica , Factor I del Crecimiento Similar a la Insulina/genética , Hígado/fisiología , Señales de Clasificación de Proteína/genética , Envejecimiento , Animales , Elementos sin Sentido (Genética) , Secuencia de Bases , Deleción Cromosómica , Clonación Molecular , Feto , Biblioteca de Genes , Hígado/crecimiento & desarrollo , Hígado/fisiopatología , Masculino , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos , Sondas ARN , Procesamiento Postranscripcional del ARN , ARN Mensajero/genética , ARN Mensajero/aislamiento & purificación , Ratas , Ratas Endogámicas , Mapeo Restrictivo , Transcripción Genética
18.
Mol Endocrinol ; 9(10): 1380-95, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8544846

RESUMEN

Rat insulin-like growth factor I (IGF-I) mRNAs contain multiple 5'-untranslated regions due to the use of leader exons transcribed from several transcription initiation sites and to alternative splicing within leader exon 1. Synthetic RNAs with 5'-ends corresponding to the use of exon 1 transcription initiation sites were translated in vitro into prepro-IGF-I peptides initiated at a Met-48 codon in exon 1 or a Met-22 codon in exon 3, and RNAs with a 5'-end corresponding to the major exon 2 transcription start site were translated into a prepro-IGF-I peptide initiated at a Met-32 codon in exon 2. All forms of prepro-IGF-I were processed by canine pancreatic microsomes, suggesting that all these prepeptides function as signal peptides. The translational efficiency of IGF-I RNAs was inversely proportional to the length of the 5'-untranslated region. Mutation of the first of three upstream AUG codons in exon 1, which potentially initiates a 14-amino acid open reading frame, did not affect prepro-IGF-I translation. The other two AUG codons are immediately followed by stop codons. The absence of both upstream AUG codons in a completely spliced exon 1-derived RNA enhanced the in vitro and in vivo translatability of this RNA as compared with the full-length RNA. Mutation of the downstream initiation codon in particular increased translational efficiency in vitro and in intact cells, suggesting that an inefficient reinitiation event at the Met-48 codon contributes to the poorer translation of IGF-I mRNAs in which these upstream AUGUGA motifs occur. We conclude that IGF-I mRNAs potentially encode multiple forms of preproIGF and that specific differences in their 5'-untranslated regions provide a molecular basis for translational control of IGF-I biosynthesis.


Asunto(s)
Factor I del Crecimiento Similar a la Insulina/genética , Biosíntesis de Proteínas , Señales de Clasificación de Proteína/genética , ARN Mensajero/metabolismo , Animales , Secuencia de Bases , Perros , Factor I del Crecimiento Similar a la Insulina/metabolismo , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Señales de Clasificación de Proteína/metabolismo , Ratas , Análisis de Secuencia
19.
Exp Hematol ; 27(2): 282-92, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10029168

RESUMEN

The possibility that mature lymphocytes play a role in the regulation of human T cell development was studied in the experimental model of fetal thymus organ cultures (FTOC), by reconstituting lymphocyte-depleted murine fetal thymus (FT) lobe with cells isolated from human umbilical cord blood (CB). Cultures were incubated with human cytokines (IL-7, FLT-3 ligand and Steel Factor), or remained untreated. When CD4+, or CD8+ CB cells, were co-cultured with FT explants, they expanded and maintained their original phenotypic markers, with no significant effect of the cytokines. Cultures of human hematopoietic stem cells (CD34+) gave rise to CD4+CD8- cells, which were mainly CD3-, with no indication of further intermediate developmental stages. However, a limited number of CD4+CD8+ (double positive [DP]) cells were detected when the CD34- cells were co-cultured with CD4+ cells from the same CB samples. In contrast, FT with unseparated CB cells resulted in the different CD4/CD8 subsets, and their numbers increased in the presence of cytokines. The appearance of DP cells depended on the presence of either CD4+ or CD8+ cells in the cultured CB samples. Hence, DP cells were not detected when the CB was depleted of CD4+ and CD8- cells ("depCB") before culture, and they appeared when depCB were co-cultured with either CD4+ or CD8+ cells. In contrast, CD4+ cells inhibited the development of CD8+CD3+ cells, and this was most pronounced in the absence of the cytokines. There was no symmetrical down-regulatory effect of CD8+ cells on the development of CD4+CD3+ cells. Addition of IL-15 to the cytokine mixture led to an increased proportion of CD56+ cells in cultures of CD34+ cells. The presence of CD4+, and not CD8+ cells, interfered with this process. Our results thus imply differential effects of CD4+ and CD8+ cells on thymocytopoiesis.


Asunto(s)
Antígenos CD , Linfocitos T CD4-Positivos/citología , Linfocitos T CD8-positivos/citología , Comunicación Celular , Sangre Fetal/citología , Células Madre Hematopoyéticas/citología , Timo/citología , ADP-Ribosil Ciclasa , ADP-Ribosil Ciclasa 1 , Animales , Antígenos CD34 , Antígenos de Diferenciación , Diferenciación Celular , Técnicas de Cocultivo , Citometría de Flujo , Humanos , Glicoproteínas de Membrana , Ratones , NAD+ Nucleosidasa , Técnicas de Cultivo de Órganos , Timo/embriología
20.
Exp Hematol ; 22(2): 114-21, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8299733

RESUMEN

Human fetal liver (FL) and neonatal cord blood (CB) granulocyte-monocyte colony-forming progenitor cells (GM-CFC) are unique in their physiological environment and in certain proliferative and differentiative capacities. Tumor necrosis factor (TNF) and interferon (IFN) may inhibit or stimulate the growth of human bone marrow GM-CFC in vitro. The effects of recombinant human (rh) TNF-alpha, rhIFN-alpha, and rhIFN-tau on recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF)-stimulated clonogenic cultures of day 7 GM-CFC from FL and umbilical CB were compared with rhGM-CSF-stimulated GM-CFC from normal human bone marrow (BM). We demonstrate that, in comparison to BM progenitor cells, GM-CFC from both FL and CB were highly resistant to growth inhibition by all three cytokines. Furthermore, clonogenic growth of progenitors from FL and CB was markedly potentiated by IFN-tau in GM-CSF-stimulated cultures and was stimulated by IFN-tau in the absence of GM-CSF. Depletion of potential accessory cells resulted in a marked stimulatory response of CB cells to TNF-alpha, in the presence of GM-CSF, while it did not alter the responses to IFN. The stimulatory effects of IFN-tau and TNF-alpha may be indirectly mediated, at least in part, through induction of increased GM-CSF production and increased GM-CSF receptor expression by fetal cells. Divergent responses of myelopoietic cells, derived from various hematopoietic compartments, to regulatory actions of cytokines may provide a basis for further understanding the role of the environment in maturation and differentiation of granulocytes and monocytes.


Asunto(s)
Granulocitos/citología , Células Madre Hematopoyéticas/citología , Factor de Necrosis Tumoral alfa/farmacología , Adulto , Factor Estimulante de Colonias de Granulocitos y Macrófagos/biosíntesis , Humanos , Recién Nacido , Interferón Tipo I/farmacología , Interferón gamma/farmacología , Hígado/citología , Hígado/embriología , Proteínas Recombinantes/farmacología
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