Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Chinese Medical Journal ; (24): 472-476, 2015.
Artículo en Inglés | WPRIM | ID: wpr-357977

RESUMEN

<p><b>BACKGROUND</b>Infections remain a major cause of therapy-associated morbidity and mortality in children with acute lymphoblastic leukemia (ALL).</p><p><b>METHODS</b>We retrospectively analyzed the medical charts of 256 children treated for ALL under the CCLG-2008 protocol in Beijing Children's Hospital.</p><p><b>RESULTS</b>There were 65 infectious complications in 50 patients during vincristine, daunorubicin, L-asparaginase and dexamethasone induction therapy, including microbiologically documented infections (n = 12; 18.5%), clinically documented infections (n = 23; 35.3%) and fever of unknown origin (n = 30; 46.2%). Neutropenia was present in 83.1% of the infectious episodes. In all, most infections occurred around the 15 th day of induction treatment (n = 28), and no patients died of infection-associated complications.</p><p><b>CONCLUSIONS</b>The infections in this study was independent of treatment response, minimal residual diseases at the end of induction therapy, gender, immunophenotype, infection at first visit, risk stratification at diagnosis, unfavorable karyotypes at diagnosis and morphologic type. The infection rate of CCLG-2008 induction therapy is low, and the outcome of patients is favorable.</p>


Asunto(s)
Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Antineoplásicos , Usos Terapéuticos , China , Daunorrubicina , Usos Terapéuticos , Dexametasona , Usos Terapéuticos , Neoplasia Residual , Leucemia-Linfoma Linfoblástico de Células Precursoras , Quimioterapia , Microbiología , Estudios Retrospectivos , Vincristina , Usos Terapéuticos
2.
Chinese Medical Journal ; (24): 338-344, 2012.
Artículo en Inglés | WPRIM | ID: wpr-262613

RESUMEN

<p><b>BACKGROUND</b>The growing enthusiasm for coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) is emerging, but the role of off-pump coronary artery bypass (OPCAB) in clinical practice remains controversial. The purpose of this study was to assess differences in the incidences of stroke, atrial fibrillation (AF), and myocardial infarction (MI) between OPCAB and conventional coronary artery bypass grafting (CCABG) by meta-analyses of randomized clinical trials.</p><p><b>METHODS</b>A literature search for the period before March 2010 supplemented with manual bibliographic review was performed for all Chinese or English publications in Medline, the Science Citation Index Expanded, the Cochrane Central Register of Controlled Trials (CENTRAL) and CBMdisc. A systematic overview (meta-analyses) of randomized clinical trials was conducted to evaluate the differences between OPCAB and CCABG in the incidences of stroke, AF, and MI. The meta-analysis was performed using RevMan 5 software.</p><p><b>RESULTS</b>Forty-three randomized clinical trials were selected for meta-analysis after screening a total of 356 references, with 8104 patients in the OPCAB group and 8724 cases in the CCABG group. The meta-analyses of these trials showed no significant difference between OPCAB and CCABG in the incidences of stroke (odds ratio (OR) = 0.80, 95% confidence interval (CI) = 0.52 - 1.22, P = 0.30) and MI (OR = 0.73, 95%CI = 0.52 - 1.02, P = 0.06). However, we found a significantly reduced risk of AF (OR = 0.65, 95%CI = 0.52 - 0.82, P = 0.0002) in off-pump patients.</p><p><b>CONCLUSIONS</b>Our meta-analyses suggest that OPCAB reduces the risk of postoperative AF compared with CCABG, but there is no significant difference in the incidences of stroke and MI between OPCAB and CCABG.</p>


Asunto(s)
Femenino , Humanos , Masculino , Persona de Mediana Edad , Fibrilación Atrial , Puente de Arteria Coronaria , Puente de Arteria Coronaria Off-Pump , Incidencia , Infarto del Miocardio , Ensayos Clínicos Controlados Aleatorios como Asunto , Accidente Cerebrovascular , Resultado del Tratamiento
3.
Chinese Medical Journal ; (24): 3495-3498, 2011.
Artículo en Inglés | WPRIM | ID: wpr-336540

RESUMEN

<p><b>BACKGROUND</b>Video-assisted thoracic sympathetic block is an effective, safe, and minimally invasive method for treatment of primary hyperhidrosis. The purpose of this study was to decide which one of using electrocautery hook and titanium clip is the appropriate procedure for primary palmar hyperhidrosis by assessing the compensatory sweating (CS) and quality of life (QOL) of patients after sympathetic block.</p><p><b>METHODS</b>Between October 2007 to August 2010, 120 patients with primary palmar hyperhidrosis were randomly divided into two groups, electrocautery hook group (60 patients) and titanium clip group (60 patients). All patients were treated by sympathetic block at T4 level. The CS was graded based on severity and location; the QOL was classified to 5 different levels based upon the summed total scores (range from 20 to 100) before and after surgery. The variables were compared.</p><p><b>RESULTS</b>The postoperative follow-up period was 2 months. All patients were cured. Three patients in electrocautery hook group and 1 patient in titanium clip group had a unilateral pneumothorax on chest X-ray, but none of them was necessary to have chest drainage. Neither perioperative mortality nor serious complications such as cardiac arrhythmia or arrest were observed during the operation. No bradycardia or Horner's syndrome occured. CS was not more common in patients in titanium clip group than in those in electrocautery hook group (P = 0.001). Moderate and severe CS was few in all patients, and there was no significant difference between two groups (P = 0.193). Most of the patients feel a notable improvement of the the QOL; nevertheless, there was no significant difference between the groups (P = 0.588).</p><p><b>CONCLUSIONS</b>Both electrocautery hook and titanium clip used for sympathetic block at the T4 level are effective, safe, and minimally invasive for palmar hyperhidrosis. Because of the lower severity of CS and the similar improvements in the QOL after operation, we prefer to use of titanium clip for treating palmar hyperhidrosis.</p>


Asunto(s)
Adulto , Femenino , Humanos , Masculino , Adulto Joven , Bloqueo Nervioso Autónomo , Métodos , Hiperhidrosis , Cirugía General , Complicaciones Posoperatorias , Calidad de Vida , Sudoración , Fisiología , Sistema Nervioso Simpático , Cirugía General , Titanio , Resultado del Tratamiento
4.
Chinese Medical Journal ; (24): 3159-3163, 2011.
Artículo en Inglés | WPRIM | ID: wpr-319181

RESUMEN

<p><b>BACKGROUND</b>Indoleamine-2,3-dioxygenase (IDO) is proven to suppress hepatitis B virus (HBV) specific immune response and depletion of IDO may be a useful approach for HBV therapy. To test this concept, we constructed recombinant adenovirus with human IDO and HBV preS, which would form the basis for future in vivo experiments.</p><p><b>METHODS</b>The fragment of human IDO and HBV preS cDNA were subcloned into multiple cloning sites in an adenoviral vector system containing two cytomegalovirus (CMV) promoters. Recombination was conducted in the Escherichia coli BJ5183. The recombinant adenovirus containing hIDO gene and HBVpreS gene was packaged and amplified in 293 cells. Integration was confirmed by polymerase chain reaction as well as the quantification of viral titers. HepG2 cells were infected with the recombinant adenovirus and mRNA and protein specific for hIDO and HBVpreS was detected by RT-PCR and Western blotting respectively.</p><p><b>RESULTS</b>The recombinant adenovirus was produced successfully. Its titer was 2.5 × 10(9) efu/ml. IDO and HBVpreS mRNA as well as the encoded proteins could be found in transfected HepG2 cells, but not in control HepG2 cells.</p><p><b>CONCLUSION</b>The transfer of hIDO-HBVpreS with double-promoter adenoviral vector was efficient. The recombinant adenovirus with hIDO and HBV preS would provide the experimental basis for future studies.</p>


Asunto(s)
Humanos , Adenoviridae , Genética , Clonación de Organismos , Vectores Genéticos , Células Hep G2 , Virus de la Hepatitis B , Genética , Indolamina-Pirrol 2,3,-Dioxigenasa , Genética , Recombinación Genética
5.
Chinese Medical Journal ; (24): 3238-3243, 2011.
Artículo en Inglés | WPRIM | ID: wpr-319138

RESUMEN

<p><b>BACKGROUND</b>X-linked inhibitor of apoptosis (XIAP)-associated factor 1 (XAF1) is a new tumor suppressor. Low expression of XAF1 is associated with poor prognosis of human cancers. However, the effect of XAF1 on lung cancer remains unknown. In this study, we investigated the expression of XAF1 and its role in squamous cell lung cancer.</p><p><b>METHODS</b>Cancer tissues, cancer adjacent tissues and normal lung tissues were collected from 51 cases of squamous cell lung cancer. The expression of XAF1 mRNA was determined by reverse transcription-polymerase chain reaction (RT-PCR). The expression of XAF1 protein was determined by Western blotting and immunohistochemical staining. Ad5/F35-XAF1 virus was generated. Cell proliferation and apoptosis were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and flow cytometry (FACS), respectively.</p><p><b>RESULTS</b>The levels of XAF1 protein and mRNA in cancer tissues were significantly lower than those in cancer adjacent and normal lung tissues (P < 0.05). The low expression of XAF1 was associated with tumor grade, disease stage, differentiation status and lymph node metastasis in squamous cell lung cancer patients. The restoration of XAF1 expression mediated by Ad5/F35-XAF1 virus significantly inhibited cell proliferation and induced apoptosis in a dose- and time-dependent manner.</p><p><b>CONCLUSION</b>XAF1 is a valuable prognostic marker in squamous cell lung cancer and may be a potential candidate gene for lung cancer therapy.</p>


Asunto(s)
Humanos , Apoptosis , Genética , Fisiología , Western Blotting , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular , Genética , Fisiología , Citometría de Flujo , Inmunohistoquímica , Péptidos y Proteínas de Señalización Intracelular , Genética , Metabolismo , Neoplasias Pulmonares , Genética , Metabolismo , Proteínas de Neoplasias , Genética , Metabolismo , Neoplasias de Células Escamosas , Genética , Metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
6.
Chinese Medical Journal ; (24): 907-911, 2010.
Artículo en Inglés | WPRIM | ID: wpr-242547

RESUMEN

<p><b>BACKGROUND</b>In clinical liver transplantation, whether the delay of hepatic arterial ischaemia increases biliary fibrosis or not is controversial. We designed a liver transplantation model to test this controversy and explore its mechanism.</p><p><b>METHODS</b>Twelve dogs were divided into two groups randomly: hepatic arterial ischaemia (HAI) and control groups. In HAI group, hepatic artery was perfused 60 minutes after portal perfusion, but in control group, hepatic arterial perfusion was simultaneous with portal perfusion. The pathological changes of intrahepatic bile ducts were observed. Transforming growth factor beta 1 (TGF-beta1), expressed in epithelial cells of intrahepatic bile duct, was detected by immunohistochemical streptoadividin-biotin complex method. Expressions of Smad3, P-Smad3 and the transcriptional levels of alpha smooth muscle actin (alpha-SMA) mRNA in intrahepatic bile ducts were detected by Western blotting and RT-PCR respectively.</p><p><b>RESULTS</b>Compared with the control group, more collagen deposition and leucocytic infiltration could be seen in biliary vessel walls. Significantly more buffy particles, which are the proteins of TGF-beta1, could be seen in biliary epithelial cells. P-Smad3 and alpha-SMA mRNA (as ratio to corresponding beta-actin) in intrahepatic bile ducts were 1.82 +/- 0.18 and 1.86 +/- 0.73 respectively in HAI group, significantly higher than those in control group (0.59 +/- 0.09 and 0.46 +/- 0.18, respectively).</p><p><b>CONCLUSIONS</b>Hepatic arterial ischaemia could increase the deposition of collagen fibres, trigger the transdifferentiation of myofibroblasts in intrahepatic bile duct and might result in biliary fibrosis by activating the TGF-beta1 signalling pathway.</p>


Asunto(s)
Animales , Perros , Masculino , Actinas , Genética , Western Blotting , Modelos Animales de Enfermedad , Arteria Hepática , Inmunohistoquímica , Isquemia , Metabolismo , Cirrosis Hepática Biliar , Metabolismo , Cirrosis Hepática Experimental , Trasplante de Hígado , Distribución Aleatoria , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteína smad3 , Metabolismo , Factor de Crecimiento Transformador beta1 , Metabolismo
7.
Chinese Medical Journal ; (24): 1525-1528, 2009.
Artículo en Inglés | WPRIM | ID: wpr-292677

RESUMEN

<p><b>BACKGROUND</b>Video-assisted thoracoscopic sympathectomy had replaced open surgery. The aim of this study was to compare the outcomes of using a single port and two ports to perform video-assisted thoracoscopic sympathectomy for palmar hyperhidrosis.</p><p><b>METHODS</b>Between April 2006 and February 2008, 20 cases underwent video-assisted thoracoscopic sympathectomy through one port (uniportal group) and 25 cases through two ports (biportal group). The variables including the operating time, hospital stay, pain scores, postoperative complications, incidence of symptom recurrence and patient satisfaction were compared. The mean postoperative follow-up period was 11.5 months (range, 3 - 25 months).</p><p><b>RESULTS</b>The hands of all patients were warm and dry after operation. No conversion to open surgery was necessary, and no operative mortality was recorded in either group. The mean inpatient pain scores were significantly higher in the biportal group (1.2 +/- 0.6) than that in the uniportal group (0.8 +/- 0.5, P = 0.025). For the first three weeks after operation, four out of 20 (20%) patients in the uniportal group constantly suffered from mild or moderate residual pain while eight out of 25 (32%) cases in the biportal group (P = 0.366). Among them, two cases in the uniportal group and five cases in the biportal group need to take analgesics. Our mean operative time (bilateral sympathectomy) in the uniportal group ((39.5 +/- 10.0) minutes) was shorter than that in biportal group ((49.7 +/- 10.6) minutes, P = 0.02). There were no significant differences between two groups in terms of the mean hospital stay, compensatory sweating, and patient satisfaction. Two patients in the biportal group and three in the uniportal group experienced a unilateral pneumothorax. None of them required chest drainage. No patient experienced Horner's syndrome, and no recurrent symptoms were observed in either groups.</p><p><b>CONCLUSIONS</b>Both uniportal and biportal video-assisted thoracoscopic sympathectomy are effective, safe, and minimally invasive for palmar hyperhidrosis. Comparing with the biportal approach, the uniportal approach causes less postoperative pain and less operative time, and is a more reasonable procedure in treatment of palmar hyperhidrosis.</p>


Asunto(s)
Adulto , Femenino , Humanos , Masculino , Mano , Cirugía General , Hiperhidrosis , Cirugía General , Simpatectomía , Métodos , Cirugía Torácica Asistida por Video , Métodos
8.
Journal of Southern Medical University ; (12): 205-208, 2009.
Artículo en Chino | WPRIM | ID: wpr-339030

RESUMEN

<p><b>OBJECTIVE</b>To investigate the role of indoleamine 2,3-dioxygenase (IDO) in immune tolerance in patients with chronic hepatitis B (CHB).</p><p><b>METHODS</b>Peripheral venous blood samples were collected from 50 CHB patients, and HBV viral load, T lymphocyte subsets and of IDO mRNA, protein and activity were detected with the blood samples from 50 healthy donors as the control. The correlations between HBV viral load, T lymphocyte subsets and IDO were statistically analyzed.</p><p><b>RESULTS</b>In CHB patients, the mRNA and protein levels and activity of IDO were all significantly higher than those in control group [mRNA: (2.110-/+0.615)x10(3) vs (0.143-/+0.026)x10(3); protein: 0.22-/+0.06 vs 0.02-/+0.0017; activity: 26.07-/+8.12 vs 4.98-/+1.65; P<0.05]. IDO mRNA level was positively correlated to HBV viral load (r=0.502, P<0.001) and ALT (r=0.65, P<0.01), and IDO mRNA, protein and activity were inversely correlated to CD4+ T cells (r=-0.622, -0.682, and -0.549, respectively, P<0.05), CD8+ T cells (r=-0.487, -367, and -294, respectively, P<0.05) and the ratio of CD4/CD8 (r=-0.426, -0.533, and -0.397, respectively, P<0.05).</p><p><b>CONCLUSION</b>IDO is closely correlated to HBV viral load and responsible for immunotolerance against HBV. Suppression of IDO can be a new therapeutic approach to reverse immunotolerance in CHB.</p>


Asunto(s)
Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Estudios de Casos y Controles , Hepatitis B Crónica , Alergia e Inmunología , Virología , Tolerancia Inmunológica , Alergia e Inmunología , Indolamina-Pirrol 2,3,-Dioxigenasa , Sangre , Alergia e Inmunología , ARN Mensajero , Sangre , Subgrupos de Linfocitos T , Alergia e Inmunología
9.
Chinese Journal of Surgery ; (12): 694-696, 2008.
Artículo en Chino | WPRIM | ID: wpr-245515

RESUMEN

<p><b>OBJECTIVE</b>To investigate the effects on lymphangiogenesis and angiogenesis of orthotopic implantation of lung cancer in nude mice with antisense oligonucleotides of VEGF-C.</p><p><b>METHODS</b>The model in nude mice was established with orthotopic implantation for the human lung cancer cell line A549. Thirty nude mice were randomized into three groups: PBS control group, sense oligonucleotides control group and antisense oligonucleotides group (AODN group). After treatments were completed, the expression of VEGF-C and lymphatic microvessel density (LMVD) and microvessel density (MVD) of lung cancer were detected by RT-PCR,Western Blot and immunohistochemistry.</p><p><b>RESULTS</b>The expression of VEGF-C in AODN group was inhibit significantly (P < 0.05). The LMVD in AODN group was decreased significantly (P < 0.1). Though the MVD in AODN group was also decreased, but there were no significant differences compared with control groups (P > 0.05).</p><p><b>CONCLUSIONS</b>The antisense oligonucleotides of VEGF-C can inhibit the expression of VEGF-C in nude mice of orthotopic implantation of lung cancer. It could inhibit the lymphangiogenesis.</p>


Asunto(s)
Animales , Femenino , Humanos , Ratones , Línea Celular Tumoral , Modelos Animales de Enfermedad , Liposomas , Neoplasias Pulmonares , Metabolismo , Patología , Linfangiogénesis , Ratones Endogámicos BALB C , Ratones Desnudos , Microvasos , Patología , Neovascularización Patológica , Quimioterapia , Oligonucleótidos Antisentido , Farmacología , Distribución Aleatoria , Transfección , Factor C de Crecimiento Endotelial Vascular , Genética , Metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
10.
Chinese Medical Journal ; (24): 703-707, 2007.
Artículo en Inglés | WPRIM | ID: wpr-344826

RESUMEN

<p><b>BACKGROUND</b>The multidrug resistance (MDR) associated with the expression of the mdr1 gene and its product P-glycoprotein is a major factor in the prognosis of hepatocellular carcinoma cell (HCC) patients treated with chemotherapy. Our study was to establish a stable HCC MDR cell line where a de novo acquisition of multidrug resistance specifically related to overexpression of a transgenic mdr1.</p><p><b>METHODS</b>The 4.5-kb mdr1 cDNA obtained from the plasmid pHaMDR1-1 was cloned into the PCI-neo mammalian expression vector, later was transferred by liposome to human hepatocarcinoma cell line HepG2. Then the transfected HepG2 cells resisting G418 were clustered and cultured and the specific fragment of mdr1 cDNA, mRNA and the P-glycoprotein (Pgp) in these HepG2 cells were detected by PCR, RT-PCR and flow cytometry, respectively. The accumulation of the daunorubicin was determinated by flow cytometry simultaneously. The nude mice model of grafting tumour was established by injecting subcutaneously HepG2/mdr1 cells in the right axilla. When the tumour diameter reached 5 mm, adriamycin was injected into peritoneal cavity. The size and growth inhibition of tumour were evaluated.</p><p><b>RESULTS</b>The mdr1 expression vector was constructed successfully and the MDR HCC line HepG2/mdr1 developed. The PCR analysis showed that the specific fragment of mdr1 cDNA in HepG2/mdr1 cells, but not in the control group HepG2 cells. Furthermore, the content of the specific fragment of mdr1 mRNA and Pgp expression in HepG2/mdr1 cells were (59.7 +/- 7.9)% and (12.28 +/- 2.09)%, respectively, compared with (16.9 +/- 3.2)% and (3.07 +/- 1.06)% in HepG2 cells. In the nude mice HCC model, the tumour genes of both groups were identified. After ADM therapy, the mean size of HepG2 cell tumours was significantly smaller than HepG2/mdr1 cell tumours.</p><p><b>CONCLUSION</b>The approach using the transfer of mdr1 cDNA may be applicable to the development of MDR hepatocarcinoma cell line, whose MDR mechanism is known. This would provide the experimental basis of MDR research.</p>


Asunto(s)
Animales , Femenino , Humanos , Ratones , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP , Genética , Metabolismo , Carcinoma Hepatocelular , Quimioterapia , Genética , Patología , Línea Celular Tumoral , Doxorrubicina , Farmacología , Usos Terapéuticos , Resistencia a Múltiples Medicamentos , Genética , Resistencia a Antineoplásicos , Genética , Citometría de Flujo , Vectores Genéticos , Genética , Neoplasias Hepáticas Experimentales , Quimioterapia , Genética , Patología , Ratones Desnudos , Mitomicina , Farmacología , Usos Terapéuticos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ensayos Antitumor por Modelo de Xenoinjerto , Métodos
11.
Journal of Shanghai Jiaotong University(Medical Science) ; (6)2006.
Artículo en Chino | WPRIM | ID: wpr-640787

RESUMEN

Objective To investigate the effects of heparin coating on intimal hyperplasia in implanted decellularized xenografts.Methods The resected canie carotid arteries were decellularized,and heparin coating was partially performed.Eighteen rabbits were divided into non-heparin-coated group(n=9)and heparin-coated group(n=9).During implantation,only the left carotid between the anastomotic stoma was ligated.Doppler ultrasonography was performed 1,3 and 12 weeks post-implantation to measure the luminal diameter,and the hemodynamic parameters such as PSV,RI and PI were calculated.All animals were sacrificed,histological observations were conducted at 12 weeks post-implantation,and I/(I+ M)was calculated.Results Except for 1 week post-implantation in the ligated side,the luminal diameters in non-heparin -coated group were significantly smaller than that of pre-implantation.Besides,those of the non-ligated side at each time points were significantly smaller than the ligated side(P

12.
Journal of Shanghai Jiaotong University(Medical Science) ; (6)2006.
Artículo en Chino | WPRIM | ID: wpr-640460

RESUMEN

Objective To evaluate the early therapeutic effect of flail chest with pulmonary contusion by using different mode of mechanical ventilation. Methods Twenty-nine patients of flail chest with pulmonary contusion were analysed retrospectively. All the patients were treated with the ventilator Bear1000. Two groups were established: invasion group was treated with SIMV+PEEP(8 cases) and CPAP+PSV (7 cases), noninvasion group was treated with NIPPV(14 cases). Results There was no death in all the patients. CPAP+PSV was more effective than SIMV+PEEP not only in decreasing breath rate and improving hypoxemia but also in decreasing peak inspiratory pressure(P

13.
Chinese Journal of Organ Transplantation ; (12)2003.
Artículo en Chino | WPRIM | ID: wpr-676378

RESUMEN

Objective To explore the causes of biliary complications related with liver donor fol- lowing liver transplantation.Methods Ninty-nine patients with improved liver donor treatment during liver transplantation from May 2005 to April 2006 were followed up and the clinical data were ana- lyzed.At the same time,the rate of biliary complications was compared with that occurring on 43 pa- tients with unimproved liver donor treatment.Results Only 4 in 99 patients with improved liver donor treatment had biliary leakage with the rate of biliary complications being 4% in comparison with 11% in those with unimproved liver donor treatment.Conclusion The improvement of liver donor treat- ment,including shortening heat-ischemia time,completely washing bile duct and remaining the whole blood supply of bile duct,can decline the occurrence of biliary complications.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA