Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Pol J Radiol ; 88: e231-e237, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37346424

RESUMEN

Purpose: To evaluate the computed tomography findings of intersigmoid hernias. Material and methods: Between April 2010 and March 2018, 7 patients who were surgically diagnosed with intersigmoid hernia in 3 institutions were enrolled in this study. Two radiologists evaluated imaging findings for the herniated small bowel, the distance between the occlusion point and bifurcation of the left common iliac artery, and the anatomic relationship with adjacent organs. Results: All patients were male, and their mean age (standard deviation, range) was 61.0 (13.5, 36-85) years. The mean size of the bowel loops was 5.2 (1.3, 4.0-8.3) cm in the caudal direction, 3.6 (0.8, 2.5-5.1) cm in the lateral, and 3.4 (0.6, 2.5-4.7) cm in the anterior-posterior direction. The volume was 37.9 (27.8, 15.6-103.0) cm3 approximated by an ellipse, and 24.0 (17.7, 9.9-65.6) cm3 approximated by a truncated cone. The obstruction point was located 3.6 (0.6, 2.8-4.7) cm inferior to the bifurcation of the left common iliac artery. In all cases, the small bowel ran under the point at which the inferior mesenteric vessels bifurcated to the superior rectal vessels and the sigmoid vessels and formed a sac-like appearance between the left psoas muscle and the sigmoid colon. The ureter ran dorsal to the point of the bowel stenosis, and the left gonadal vein ran outside the small bowel loops. Conclusions: All cases showed common imaging findings, which may be characteristic of men's intersigmoid hernia. In addition, the fossa's position was lower, and the size was larger than in the previous study, which may be a risk factor.

2.
BMC Surg ; 22(1): 302, 2022 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-35932031

RESUMEN

BACKGROUND: Day of the week when elective gastrointestinal surgery is performed may be influenced by various background and tumor-related factors. Relationships between postoperative outcome and when in the week gastrectomy is performed remain controversial. We undertook this study to evaluate whether weekday of gastrectomy influenced outcomes of gastric cancer treatment ("weekday effect"). METHODS: Patients who underwent curative surgery for gastric cancer between 2004 and 2017 were included in this retrospective study. To obtain 2 cohorts well balanced for variables that might influence clinical outcomes, patients whose gastrectomy was performed early in the week (EW group) were matched 1:1 with others undergoing gastrectomy later in the week (LW group) by use of propensity scores. RESULTS: Among 554 patients, 216 were selected from each group by propensity score matching. Incidence of postoperative complications classified as Clavien-Dindo grade II or higher was similar between EW and LW groups (20.4% vs. 24.1%; P = 0.418). Five-year overall and recurrence-free survival were 86.0% and 81.9% in the EW group, and 86.2% and 81.1% in the LW group (P = 0.981 and P = 0.835, respectively). CONCLUSIONS: Short- and long-term outcomes were comparable between gastric cancer patients who underwent gastrectomy early and late in the week.


Asunto(s)
Laparoscopía , Neoplasias Gástricas , Gastrectomía/efectos adversos , Humanos , Laparoscopía/efectos adversos , Complicaciones Posoperatorias/etiología , Puntaje de Propensión , Estudios Retrospectivos , Neoplasias Gástricas/complicaciones , Resultado del Tratamiento
3.
Surg Endosc ; 36(12): 9244-9253, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35840711

RESUMEN

BACKGROUND: Laparoscopic gastrectomy (LG) is performed widely, but whether LG is the optimal treatment for sarcopenic gastric cancer patients is unclear. This study aimed to determine whether LG is particularly beneficial for gastric cancer patients with sarcopenia. METHODS: We collected data concerning 604 consecutive patients who underwent gastrectomy for gastric cancer between January 2003 and December 2019. After adjustment using one-to-one propensity score matching, short-term and long-term outcomes were compared between LG and open gastrectomy (OG) groups among patients with sarcopenia and those without. RESULTS: Among patients with and without sarcopenia, the LG group had a significantly longer operative time but less blood loss than the OG group. The two groups showed no significant differences regarding complications. Although 5-year overall and disease-specific survival were similar between LG and OG groups among patients with and without sarcopenia, LG was associated with greater 5-year non-gastric cancer-related survival than OG among patients with sarcopenia (88.3% vs. 78.1%, P = 0.048), but not those without. CONCLUSION: LG for resectable gastric cancer was not inferior to OG regarding complications and outcomes in patients with or without sarcopenia. No difference in overall survival was evident between these approaches, but LG may lessen mortality from conditions unrelated to gastric cancer in sarcopenic patients.


Asunto(s)
Laparoscopía , Sarcopenia , Neoplasias Gástricas , Humanos , Puntaje de Propensión , Sarcopenia/complicaciones , Sarcopenia/cirugía , Gastrectomía/efectos adversos , Neoplasias Gástricas/complicaciones , Neoplasias Gástricas/cirugía , Laparoscopía/efectos adversos , Estudios Retrospectivos , Resultado del Tratamiento
4.
Clin Nutr ; 41(7): 1467-1474, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35662018

RESUMEN

BACKGROUND & AIMS: Preoperative low skeletal muscle mass and obesity have been identified as poor prognostic factors after gastrectomy for cancer, but the predictive value of combined quantitation of skeletal muscle mass and obesity remains unclear. This study examined the impact of combined body compositions on outcomes after gastrectomy for cancer. METHODS: 518 patients who had undergone gastric resection for cancer between 2004 and 2017 were analyzed retrospectively. Skeletal muscle mass (skeletal muscle mass index (SMI)) and visceral obesity (visceral fat area) were measured in preoperative computed tomographic images to categorize patients as outlined below. Impacts of these body compositions on outcomes after gastrectomy were investigated. RESULTS: Body composition was classified as high SMI without obesity in 231 patients (45%), high SMI with obesity in 202 (39%), low SMI without obesity in 55 (11%), and low SMI with obesity in 30 (6%). Postoperative complications developed in 128 patients (25%). Multivariate analysis identified low SMI with obesity as an independent risk factor for postoperative complications (odds ratio, 3.27; P = 0.010). Moreover, patients with low SMI without obesity had lower 5-year overall survival rates than patients with high SMI without obesity (64.4% vs. 88.0%; P < 0.001) and worse 5-year relapse-free survival rates (61.3% vs. 81.3%; P = 0.002). Multivariate analysis identified low SMI without obesity as a significant risk factor for overall survival (hazard ratio, 3.033; P < 0.001) and relapse-free survival (hazard ratio, 2.144; P = 0.008) after gastrectomy. CONCLUSION: Preoperative low SMI with obesity was an independent risk factor for postoperative complications, while low SMI without obesity was an independent risk factor for overall and relapse-free survival following gastrectomy for cancer.


Asunto(s)
Sarcopenia , Neoplasias Gástricas , Tejido Adiposo/diagnóstico por imagen , Composición Corporal/fisiología , Gastrectomía/efectos adversos , Humanos , Músculo Esquelético/fisiología , Recurrencia Local de Neoplasia , Obesidad/complicaciones , Obesidad/cirugía , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Pronóstico , Estudios Retrospectivos , Sarcopenia/complicaciones , Sarcopenia/diagnóstico por imagen , Neoplasias Gástricas/complicaciones , Neoplasias Gástricas/cirugía
6.
Surg Today ; 51(7): 1135-1143, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33491103

RESUMEN

PURPOSE: It is known that sarcopenia affects the overall short- and long-term outcomes of patients with gastric cancer (GC); however, the effect of muscle quality on infectious complications after gastrectomy for GC remains unclear. We investigated the associations between the preoperative quantity and quality of skeletal muscle on infectious complications following gastrectomy for GC. METHODS: The subjects of this retrospective study were 353 GC patients who underwent radical gastrectomy between 2009 and 2018. We examined the relationships between their clinical factors, including skeletal muscle mass index and intramuscular adipose tissue content (IMAC), and infectious complications after gastrectomy. RESULTS: Infectious complications developed in 59 patients (16.7%). The independent risk factors for infectious complications identified by multivariate analysis were male gender (P < 0.001), prognostic nutritional index below 45 (P = 0.006), and high IMAC (P = 0.011). Patients with a high IMAC were older and had a higher body mass index, as well as a greater age-adjusted Charlson comorbidity index, than those with low or normal IMAC. CONCLUSIONS: Low skeletal muscle quality defined by a high IMAC is a risk factor for infectious complications following gastrectomy. When feasible, preoperative nutritional intervention and rehabilitation aiming to improve muscle quality could reduce infectious complications after gastrectomy for GC.


Asunto(s)
Gastrectomía/efectos adversos , Músculo Esquelético/patología , Complicaciones Posoperatorias/etiología , Neoplasias Gástricas/cirugía , Infección de la Herida Quirúrgica/etiología , Anciano , Índice de Masa Corporal , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/diagnóstico por imagen , Evaluación Nutricional , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control , Factores de Riesgo , Sarcopenia/complicaciones , Sarcopenia/diagnóstico por imagen , Sarcopenia/patología , Neoplasias Gástricas/complicaciones , Infección de la Herida Quirúrgica/epidemiología , Infección de la Herida Quirúrgica/prevención & control , Tomografía Computarizada por Rayos X
7.
Jpn J Radiol ; 39(6): 558-563, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33462730

RESUMEN

Entamoeba histolytica is distributed throughout the world. Invasive amebiasis affects millions of people globally, and the associated complications cause 40,000-100,000 deaths per year. In countries where fecal-oral transmission is unusual, amebic colitis is not common, and the infection may be seen in travelers to and emigrants from endemic areas. Without adequate treatment, amebic colitis may develop into fulminant and become rapidly fatal. With the current increase in global mobility, amebic colitis should be suspected even in patients not in the endemic areas. CT plays an important role in the diagnosis of amebic colitis by demonstrating the presence of colitis with the typical involvement of the cecum and rectum. Pathological features of atypical involvement are also demonstrated. Since preoperative diagnosis can reduce the mortality associated with necrotizing colitis, radiologists need to recognize the typical as well as atypical CT findings of amebic colitis. Considering this requirement, this paper aims to describe the histopathologic features of amebic colitis and to illustrate the spectrum of corresponding CT findings.


Asunto(s)
Disentería Amebiana/diagnóstico por imagen , Entamoeba histolytica , Entamebiasis/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Tracto Gastrointestinal/diagnóstico por imagen , Tracto Gastrointestinal/parasitología , Humanos , Masculino
8.
Asian J Endosc Surg ; 12(3): 269-274, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30178535

RESUMEN

INTRODUCTION: Generally, laparoscopic colorectal surgery is performed with the patient in the lithotomy and rotated positions. The lithotomy position, however, is associated with intraoperative peripheral nerve injury (IPNI). We studied the relationship between patient positioning during laparoscopic colorectal surgery, contact pressure at the shoulder, and the occurrence of IPNI and tested a positioning protocol aimed at surgical safety in addition to maintenance of a good surgical field. METHODS: We applied our positioning protocol in 44 cases and collected data that could be used to answer our study questions. We set limits for shoulder contact pressure and time in the rotation position. When the time limit was reached, we returned the patient to the supine position for 5 min. RESULTS: Patients' median age was 71 years; mean BMI was 22.4 kg/m2 . Median time in the rotation position was 126 min. For the 22 patients for whom validated data was obtained, mean lower shoulder pressure changed from 8.5 mmHg just after rotation to 11.4 mmHg 120 min after rotation (P = 0.013). Absence of IPNI in our patients confirmed the proposed relation between patient positioning and IPNI. Our data indicate that a prolonged period in the rotation position increases contact pressure at the shoulder, which can increase the risk of IPNI. CONCLUSION: Our patient positioning protocol appears to have prevented laparoscopic colectomy-related IPNI. Future studies are warranted to confirm the relationship between patient positioning and IPNI and, if necessary, to further refine the protocol to ensure prevention of IPNI during laparoscopic colorectal surgery.


Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo/efectos adversos , Complicaciones Intraoperatorias/prevención & control , Laparoscopía/efectos adversos , Posicionamiento del Paciente , Traumatismos de los Nervios Periféricos/prevención & control , Adulto , Anciano , Anciano de 80 o más Años , Protocolos Clínicos , Femenino , Humanos , Complicaciones Intraoperatorias/etiología , Masculino , Persona de Mediana Edad , Tempo Operativo , Traumatismos de los Nervios Periféricos/etiología , Presión , Rotación , Hombro
9.
Sensors (Basel) ; 18(12)2018 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-30513874

RESUMEN

Diagnoses of power transformers by partial discharge (PD) measurement are effective to prevent dielectric failures of the apparatus. Ultra-high frequency (UHF) method has recently received attention due to its various advantages, such as the robustness against external noise and the capability of PD localization. However, electromagnetic (EM) waves radiated from PD tend to suffer attenuation before arriving at UHF sensors, because active part of the transformer disturbs the EM wave propagation. In some cases, that results in poor detection sensitivity. To understand propagation and attenuation characteristics of EM waves and to evaluate the detection sensitivity quantitatively, a computational approach to simulate the EM wave propagation is important. Although many previous researches have dealt with EM wave simulation for transformers, validations of those simulations by comparing with the experimental ones have seldom been reported. In this paper, cumulative energies, signal amplitudes and propagation times of EM waves were measured using a 630 kVA transformer. EM wave propagation was computed using the time-domain finite integration technique and the results were compared with the experimentally obtained ones. These simulation results showed good agreement with the experimental ones. The results can serve as guidelines to improve the efficiency of UHF PD detection and offer the possibility to achieve optimal placement of UHF sensors in power transformers.

10.
Oncogene ; 37(9): 1205-1219, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29242607

RESUMEN

Carcinoma-associated fibroblasts (CAFs) influence tumor initiation, progression, and metastasis within the tumor-associated stroma. This suggests that CAFs would be a potential target for tumor therapy. Here we found that Hydrogen peroxide-inducible clone-5 (Hic-5), also named transforming growth factor beta-1-induced transcript 1 protein (Tgfb1i1), was strongly induced in CAFs found in human colorectal cancer. To investigate the role of Hic-5 in CAFs, we isolated CAFs and the control counterpart normal fibroblasts (NFs) from human colorectal cancer and non-cancerous regions, respectively. Hic-5 was highly expressed in isolated human CAFs and strongly induced in NFs in culture by the supernatant from cultured colorectal cancer cells as well as cytokines such as TGF-ß, IL-1ß and stromal cell-derived factor 1 (SDF-1/CXCL12). Furthermore, tumor growth was inhibited in a co-culture assay with Hic-5 knockdown fibroblasts compared with control fibroblasts. To clarify the function and significance of Hic-5 in colorectal cancer in vivo, we utilized a mouse model of azoxymethane (AOM)-induced colorectal cancer using Hic-5-deficient mice. Lack of Hic-5 in CAFs completely prevented AOM-induced colorectal cancer development in the colon tissues of mice. Mechanistic investigation revealed that Hic-5 promoted the expression of lysyl oxidase and collagen I in human control counterpart fibroblasts. Taken together, these results demonstrate that Hic-5 in CAFs is responsible for orchestrating or generating a tumor-promoting stroma.


Asunto(s)
Fibroblastos Asociados al Cáncer/patología , Carcinogénesis/patología , Neoplasias Colorrectales/patología , Proteínas del Citoesqueleto/fisiología , Proteínas de Unión al ADN/fisiología , Fibroblastos/patología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas con Dominio LIM/metabolismo , Proteínas con Dominio LIM/fisiología , Células del Estroma/patología , Animales , Apoptosis , Azoximetano/toxicidad , Biomarcadores de Tumor , Fibroblastos Asociados al Cáncer/metabolismo , Carcinogénesis/metabolismo , Proliferación Celular , Técnicas de Cocultivo , Neoplasias Colorrectales/inducido químicamente , Neoplasias Colorrectales/metabolismo , Fibroblastos/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas con Dominio LIM/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Pronóstico , Proteína-Lisina 6-Oxidasa , Transducción de Señal , Células del Estroma/metabolismo , Células Tumorales Cultivadas
11.
Gan To Kagaku Ryoho ; 41(7): 909-12, 2014 Jul.
Artículo en Japonés | MEDLINE | ID: mdl-25131883

RESUMEN

CASE: A 69-year-old man was diagnosed with advanced esophageal cancer(well-differentiated squamous cell carcinoma). Neoadjuvant chemotherapy consisting of nedaplatin and 5-fluorouracil(5-FU)was initiated. After two courses of chemotherapy, the patient was judged to have achieved a clinical complete response. The patient then decided against undergoing surgery and opted instead to continue with the chemotherapy, receiving five courses in total. However, the esophageal cancer recurred, and subtotal esophagectomy was performed in January 2011. Squamous cell carcinoma with an adenocarcinoma component, which consisted of poorly differentiated squamous cell carcinoma and tubular adenocarcinoma cells, was observed at the primary site. Metastasis of the cancer to the liver was detected 2 months after surgery. The subsequent administration of four courses of docetaxel to the patient did not result in any beneficial effects, and the patient developed carcinomatous pleurisy and died of this complication in November 2011. The patient survived for a total of 21 months after starting chemotherapy. In this case, the chemotherapy itself may have resulted in the dedifferentiation of a well differentiated squamous cell carcinoma to result in a poorly differentiated squamous cell carcinoma with an adenocarcinoma component.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Neoplasias Esofágicas/tratamiento farmacológico , Adenocarcinoma/cirugía , Anciano , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/cirugía , Diferenciación Celular , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/cirugía , Carcinoma de Células Escamosas de Esófago , Fluorouracilo/administración & dosificación , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/secundario , Masculino , Compuestos Organoplatinos/administración & dosificación , Recurrencia
12.
Case Rep Oncol ; 7(2): 330-6, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24987352

RESUMEN

A 75-year-old man was diagnosed with gastric cancer. Fifty years previously, he had undergone gastroenterostomy with a Braun enteroenterostomy. At present, a distal gastrectomy and small intestinal partial resection were performed. Intraoperatively, the tumor was localized to the previous stomal site. HE staining showed that the tumor comprised two elements: a tubular adenocarcinoma on the gastric side and a neuroendocrine carcinoma (NEC) on the jejunal side. The final pathologic diagnosis was mixed adenoneuroendocrine carcinoma based on an immunohistochemical analysis of endocrine markers and an elevated Ki-67 labeling index. The risk of later cancer development cancer recurrence near the gastrojejunostomy site is well known. Potentially, chronic enterogastric bile reflux may irritate the gastric mucosa and act as a promoter. Gastric NEC has a strong malignant potential. We suspect that, in the present case, the constant exposure to secondary bile may have induced a gastric mucosal adenocarcinoma, which finally differentiated into a NEC.

13.
J Toxicol Sci ; 37(4): 699-709, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22863851

RESUMEN

In the present study, we isolated and determined the pharmacological characteristics of a novel gene encoding the zinc finger-like protein (ZfLp). The isolated cDNA consisted of 1,581 base pairs that encoded a 526-amino acid protein. The amino acid sequence of ZfLp is 96% identical to that of zinc finger protein 415 isoform 5 (ZNF415-5). Reverse-transcription (RT)-polymerase chain reaction (PCR) analysis revealed that the ZfLp mRNA is expressed in the breast, lung, stomach, small intestine colon and ovary, but not in the liver. When expressed in Xenopus laevis oocytes, ZfLp mediated the high affinity transport of [(3)H]paclitaxel (taxol) in a sodium-independent manner (K(m) = 336.7 ± 190.0 nM). The uptake of [(3)H]paclitaxel (taxol) by ZfLp was trans-stimulated by glutarate and glutathione (GSH). A cis-inhibition experiment revealed that ZfLp-mediated transport of [(3)H]paclitaxel (taxol) is inhibited by several organic solutes specifically clotrimazole. Using several clotrimazole derivatives, we found that N-benzylimidazole would be a minimum unit for producing the inhibition of ZfLp-mediated drug uptake. Our results may provide insights into the novel role of soluble protein, such as ZNF, in the human body. Our results, therefore, would be expected to facilitate research on the novel role of ZNFs and on the discovery of novel drugs for targeting ZNF-related proteins such as ZfLp.


Asunto(s)
Oocitos/metabolismo , Factores de Transcripción/metabolismo , Xenopus laevis/genética , Dedos de Zinc/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Transporte Biológico , Clonación Molecular , ADN Complementario/genética , Femenino , Regulación de la Expresión Génica , Biblioteca de Genes , Humanos , Imidazoles/química , Datos de Secuencia Molecular , Paclitaxel/farmacocinética , Filogenia , ARN Mensajero/genética , ARN Mensajero/metabolismo , Especificidad por Sustrato , Factores de Transcripción/genética , Xenopus laevis/metabolismo
14.
Drug Metab Dispos ; 38(9): 1427-35, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20547965

RESUMEN

In the present study, we isolated and determined the pharmacological characteristics of a novel gene encoding the lambda light chain of human Ig surface antigen-related gene (IgLC-rG). The isolated cDNA consisted of 693 base pairs that encoded a 232-amino acid protein. Northern blot analysis revealed that the IgLC-rG mRNA is expressed in the adult spleen and small intestine but not in fetal tissues. When expressed in Xenopus laevis oocytes, IgLC-rG mediated the high-affinity transport of [(3)H]cyclosporin A (CsA) (K(m) = 189.7 +/- 123.5 nM) in a sodium-dependent manner; however, other organic solutes such as p-aminohippuric acid and TEA were not transported via IgLC-rG. The transport of [(3)H]CsA by IgLC-rG was sensitive to pH. The uptake of [(3)H]CsA was trans-stimulated by CsA and GSH. Immunohistochemical analysis revealed that the IgLC-rG protein is localized at the brush border membrane in the human small intestine. Although the isolated IgLC-rG gene is a member of the human Ig lambda light chain surface antigen superfamily, our findings suggest that IgLC-rG functions as a novel transport peptide responsible for CsA in the human body. Our results should provide insight into the novel function of membrane-bound proteins, such as Igs.


Asunto(s)
Antígenos de Superficie/metabolismo , Ciclosporina/metabolismo , Cadenas lambda de Inmunoglobulina/metabolismo , Secuencia de Aminoácidos , Animales , Antígenos de Superficie/genética , Antígenos de Superficie/inmunología , Secuencia de Bases , ADN Complementario , Etiquetas de Secuencia Expresada , Humanos , Cadenas lambda de Inmunoglobulina/inmunología , Inmunohistoquímica , Cinética , Datos de Secuencia Molecular , Xenopus laevis
15.
Life Sci ; 84(1-2): 45-51, 2009 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-19032958

RESUMEN

AIMS: We isolated a novel gene encoding human nucleoside transporter 1 (hNT1), from a human breast cancer cDNA library. MAIN METHODS: A nondirectional cDNA library was screened by an EST clone (GenBanktrade mark/EMBL/DDBJ: BU944345). A Xenopus laevis oocyte expression system was used for functional characterization. Membrane localization in the human breast was determined by immunohistochemistry. KEY FINDINGS: Isolated hNT1 cDNA consisted of 246 base pairs that encoded an 82-amino acid protein. By RT-PCR analysis, hNT1 mRNA was strongly detected in the breast cancer tissues. When expressed in X. oocytes, hNT1 mediated the high affinity transport of [(3)H]5-fluorouracil (5-FU) with a K(m) value of 69.2+/-24.5 nM in time- and pH-dependent, and Na(+)-independent manners. A cis-inhibition experiment revealed that hNT1 mediated transport of [(3)H]5-FU is strongly inhibited by various nucleosides such as pyrimidine, uracil, uridine, guanosine, inosine, thymidine, adenosine, cytidine and purine suggesting that hNT1 may be involved in the trans epithelial transport of these endogenous substrates. Immunohistochemical analysis revealed that the hNT1 protein is localized in the lactiferous duct epithelium. SIGNIFICANCE: Our present results indicate that a newly isolated cDNA clone, hNT1, is a key molecule for the breast handling of 5-FU in humans.


Asunto(s)
Neoplasias de la Mama/metabolismo , Biblioteca de Genes , Proteínas de Transporte de Nucleósidos/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Fluorouracilo/farmacocinética , Humanos , Inmunohistoquímica , Datos de Secuencia Molecular , Proteínas de Transporte de Nucleósidos/análisis , Proteínas de Transporte de Nucleósidos/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...