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1.
World J Surg ; 45(7): 2218-2226, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33842995

RESUMEN

BACKGROUND: The impact of body compositions on surgical results is controversially discussed. This study examined whether visceral obesity, sarcopenia or sarcopenic obesity influence the outcome after hepatic resections of synchronous colorectal liver metastases. METHODS: Ninety-four consecutive patients with primary hepatic resections of synchronous colorectal metastases were identified from a single center database between January 2013 and August 2018. Patient characteristics and 30-day morbidity were retrospectively analyzed. Body fat and skeletal muscle were calculated by planimetry from single-slice CT images at the level of L3. RESULTS: Fifty-nine patients (62.8%) underwent minor hepatectomies, and 35 patients underwent major resections (37.2%). Postoperative complications occurred in 60 patients (62.8%) including 35 patients with major complications (Clavien-Dindo grade III-V). The mortality was nil at 30 days and 2.1% at 90 days. The body mass index showed no influence on postoperative outcomes (p = 1.0). Visceral obesity was found in 66 patients (70.2%) and was significantly associated with overall and major complication rates (p = .002, p = .012, respectively). Sarcopenia was observed in 34 patients (36.2%) without a significant impact on morbidity (p = .461), however, with longer hospital stay. Sarcopenic obesity was found in 18 patients (19.1%) and was significantly associated with postoperative complications (p = .014). Visceral obesity, sarcopenia and sarcopenic obesity were all identified as significant risk factors for overall postoperative complications. CONCLUSION: Visceral obesity, sarcopenic obesity and sarcopenia are independent risk factors for overall complications after resections of CRLM. Early recognition of extremes in body compositions could prompt to perioperative interventions and thus improve postoperative outcomes.


Asunto(s)
Neoplasias Colorrectales , Obesidad Abdominal , Sarcopenia , Neoplasias Colorrectales/complicaciones , Neoplasias Colorrectales/cirugía , Hepatectomía/efectos adversos , Humanos , Hígado , Obesidad/complicaciones , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Sarcopenia/complicaciones , Sarcopenia/epidemiología , Resultado del Tratamiento
2.
Chirurg ; 89(5): 374-380, 2018 May.
Artículo en Alemán | MEDLINE | ID: mdl-29464308

RESUMEN

BACKGROUND: The incidence of intrahepatic cholangiocarcinoma (ICC) is increasing worldwide. Surgical resection is the only curative treatment option. AIM OF THE STUDY: This study analyzed the prognostic factors after resection of ICC. MATERIAL AND METHODS: A total of 84 patients were surgically treated under potentially curative intent. Perihilar and distal cholangiocarcinomas were excluded. The 5­year survival was analyzed with respect to tumor stage (TNM), number of lesions, complete surgical resection (R0), peritoneal carcinosis and postoperative complications. RESULTS: The 5­year survival was 27% and 77% of patients underwent R0 resections. In the univariate analysis a T stage >2, an N+ situation or an R+ resection as well as peritoneal and multilocular intrahepatic spread were associated with a poorer prognosis. Postoperative complications also negatively influenced survival. On multivariate analysis the absence of peritoneal spread, node-negative tumor stages, singular hepatic lesions and a low T stage as well as the absence of complications were associated with improved survival. DISCUSSION: The prognosis of ICC is poor even after successful surgical resection. Well-known tumor characteristics such as TNM are relevant prognostic factors. Surgical resection is accompanied by postoperative complications (most frequently biliary), which negatively influence survival. Adjuvant strategies are urgently needed to improve long-term survival even after complete surgical resection.


Asunto(s)
Neoplasias de los Conductos Biliares , Conductos Biliares Intrahepáticos , Colangiocarcinoma , Neoplasias de los Conductos Biliares/cirugía , Colangiocarcinoma/cirugía , Hepatectomía , Humanos , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del Tratamiento
3.
Am J Transplant ; 16(4): 1139-47, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26855194

RESUMEN

Transplant recipients face an increased risk of cancer compared with the healthy population. Although several studies have examined the direct effects of immunosuppressive drugs on cancer cells, little is known about the interactions between pharmacological immunosuppression and cancer immunosurveillance. We investigated the different effects of rapamycin (Rapa) versus cyclosporine A (CsA) on tumor-reactive CD8(+) T cells. After adoptive transfer of CD8(+) T cell receptor-transgenic OTI T cells, recipient mice received either skin grafts expressing ovalbumin (OVA) or OVA-expressing B16F10 melanoma cells. Animals were treated daily with Rapa or CsA. Skin graft rejection and tumor growth as well as molecular and cellular analyses of skin- and tumor-infiltrating lymphocytes were performed. Both Rapa and CsA were equally efficient in prolonging skin graft survival when applied at clinically relevant doses. In contrast to Rapa-treated animals, CsA led to accelerated tumor growth in the presence of adoptively transferred tumor-reactive CD8(+) OTI T cells. Further analyses showed that T-bet was downregulated by CsA (but not Rapa) in CD8(+) T cells and that cancer cytotoxicity was profoundly inhibited in the absence of T-bet. CsA reduces T-bet-dependent cancer immunosurveillance by CD8(+) T cells. This may contribute to the increased cancer risk in transplant recipients receiving calcineurin inhibitors.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Ciclosporina/farmacología , Rechazo de Injerto/inmunología , Tolerancia Inmunológica/inmunología , Melanoma Experimental/inmunología , Trasplante de Piel , Proteínas de Dominio T Box/fisiología , Animales , Femenino , Rechazo de Injerto/tratamiento farmacológico , Supervivencia de Injerto/efectos de los fármacos , Supervivencia de Injerto/inmunología , Tolerancia Inmunológica/efectos de los fármacos , Inmunosupresores/farmacología , Masculino , Melanoma Experimental/tratamiento farmacológico , Melanoma Experimental/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Sirolimus/farmacología
4.
Br J Cancer ; 112(5): 841-50, 2015 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-25688743

RESUMEN

BACKGROUND: Systemic therapy has proven only marginal effects in hepatocellular carcinoma (HCC) so far. The aim of this study was to evaluate the effect of targeting fibroblast growth factor receptor (FGFR) on tumour and stromal cells in HCC models. METHODS: Human and murine HCC cells, endothelial cells (ECs), vascular smooth muscle cells (VSMCs), hepatic stellate cells (HSCs), human HCC samples, FGFR inhibitor BGJ398 and mammalian target of rapamycin (mTOR) inhibitor rapamycin were used. Effects on growth, motility, signalling and angiogenic markers were determined. In vivo subcutaneous and syngeneic orthotopic tumour models were used. RESULTS: In tumour cells and ECs, targeting FGFR showed significant inhibitory effects on signalling and motility. Minor effects of FGFR inhibition were observed on VSMCs and HSCs, which were significantly enhanced by combining FGFR and mTOR blockade. In vivo daily (5 mg kg(-1)) treatment with BGJ398 led to a significant growth inhibition in subcutaneous tumour models, but only a combination of FGFR and mTOR blockade impaired tumour growth in the orthotopic model. This was paralleled by reduced tumour cell proliferation, vascularisation, pericytes and increased apoptosis. CONCLUSIONS: Targeting FGFR with BGJ398 affects tumour cells and ECs, whereas only a combination with mTOR inhibition impairs recruitment of VSMCs and HSCs. Therefore, this study provides evidence for combined FGFR/mTOR inhibition in HCC.


Asunto(s)
Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Compuestos de Fenilurea/farmacología , Pirimidinas/farmacología , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/antagonistas & inhibidores , Sirolimus/farmacología , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Animales , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Sinergismo Farmacológico , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/patología , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Compuestos de Fenilurea/administración & dosificación , Pirimidinas/administración & dosificación , Transducción de Señal/efectos de los fármacos , Sirolimus/administración & dosificación , Ensayos Antitumor por Modelo de Xenoinjerto
5.
Zentralbl Chir ; 139(2): 212-9, 2014 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-24022245

RESUMEN

The combination of right portal vein ligation with complete parenchyma dissection ("in-situ split", ISS) for rapid hypertrophy induction of the left-lateral liver lobe is a novel strategy to convert primarily irresectable liver tumours into a resectable stage. Available data so far show a 60-80 % growth induction of the remnant liver within 7(- 9) days. Certainly, a novel concept that comprises two operations within a very short time period raises questions. Based on the very few literature reports that have been published so far, as well as our own experience, we here discuss technical issues such as the use of a plastic sheet on the resection margin, the possibility of laparoscopic dissection and the timing of the second operation. Moreover, aspects of the preoperative diagnostic work-up that is necessary are assessed. Finally, open questions, e.g., concerning the influence of preoperative chemotherapy and the use of ISS in patients with cirrhosis are evaluated. In summary, the assessment of chances and risks of this novel concept with regard to indication and technical issues helps to provide the potentially curative option of the "in-situ split" procedure to more patients with marginal or even irresectable liver tumours.


Asunto(s)
Hepatectomía/métodos , Neoplasias Hepáticas/cirugía , Regeneración Hepática/fisiología , Vena Porta/cirugía , Humanos , Hipertrofia , Laparoscopía/métodos , Ligadura , Hígado/patología , Cirrosis Hepática/patología , Cirrosis Hepática/cirugía , Neoplasias Hepáticas/patología , Terapia Neoadyuvante , Estadificación de Neoplasias , Complicaciones Posoperatorias/fisiopatología , Pronóstico
6.
Chirurg ; 83(12): 1097-108, 2012 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-23179515

RESUMEN

Techniques for biliodigestive anastomoses are a frequent indication in primary surgical interventions. Moreover, they are required to manage secondary complications of hepatobiliary surgery. Evidence for the management of complications following biliodigestive anastomoses is low. Biliodigestive anastomoses can be performed as hepaticojejunostomy, hepatojejunostomy/portoenterostomy and hepaticoduodenostomy using running or single stitch suture techniques. Complication management in the hands of experienced hepatopancreatobiliary surgeons should consider a time delay to the primary operation and an interdisciplinary surgical and/or endoscopic or radiologic interventional approach. The therapy may be protracted and requires repeated critical reflection of the particular complication.


Asunto(s)
Anastomosis Quirúrgica/métodos , Enfermedades de las Vías Biliares/cirugía , Procedimientos Quirúrgicos del Sistema Biliar/métodos , Conducta Cooperativa , Comunicación Interdisciplinaria , Complicaciones Posoperatorias/etiología , Anastomosis en-Y de Roux/métodos , Conductos Biliares/cirugía , Drenaje/métodos , Duodenostomía/métodos , Humanos , Yeyunostomía/métodos , Portoenterostomía Hepática/métodos , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/cirugía , Reoperación
7.
Biotech Histochem ; 85(6): 379-87, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20109099

RESUMEN

Tandem dimer Tomato (tdTomato) provides a useful alternative to enhanced green fluorescent protein (eGFP) for performing simultaneous detection of fluorescent protein in histological sections together with fluorescence immunohistochemistry (IHC). eGFP has many properties that make it useful for cell labeling; however, during simultaneous fluorescence IHC, the usefulness of eGFP may be limited. This limitation results from a fixation step required to identify eGFP in histological tissue sections that can mask antibody epitopes and adversely affect staining intensity. An alternative fluorescent protein, tdTomato, may assist concurrent detection of fluorescent protein within tissue sections and fluorescence IHC, because detection of tdTomato does not require tissue fixation. Tissue sections were obtained from various organs of mice ubiquitously expressing eGFP or tdTomato that were either unfixed or fixed with 4% paraformaldehyde. These tissues later were combined with fluorescence IHC. Both eGFP and tdTomato displayed robust signals in fixed frozen sections. Only tdTomato fluorescence, however, was detected in unfixed frozen sections. Simultaneous detection of fluorescence IHC and fluorescent protein in histological sections was observed only in unfixed frozen tdTomato tissue. For this reason, tdTomato is a useful substitute for eGFP for cell labeling when simultaneous fluorescence IHC is required.


Asunto(s)
Secciones por Congelación/métodos , Proteínas Fluorescentes Verdes , Proteínas Luminiscentes , Fijación del Tejido/métodos , Animales , Formaldehído , Proteínas Fluorescentes Verdes/análisis , Inmunohistoquímica/métodos , Proteínas Luminiscentes/análisis , Ratones , Ratones Transgénicos , Microscopía Fluorescente , Polímeros , Coloración y Etiquetado
8.
Zentralbl Chir ; 134(5): 443-9, 2009 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-19492282

RESUMEN

The treatment of peritoneal carcinomatosis represents a challenge in the therapy for gastrointestinal cancer. A multimodal approach with complete surgical cytoreduction and hyperthermic intraperitoneal chemotherapy can improve the prognosis in selected patients. Complete surgical cytoreduction, consisting of parietal and visceral peritonectomy, is a sophisticated procedure, frequently requiring multivisceral resections and should only be performed by experienced visceral surgeons. In addition, hyperthermic intraperitoneal chemotherapy is of some complexity. Furthermore, regarding the learning curve for this procedure, combined treatment should only be performed in specialised centres. Under optimal conditions, the therapy can be carried out with reasonable morbidity and mortality rates. Patients with peritoneal carcinomatosis should be evaluated by an interdisciplinary team concerning this multimodal therapy option and, if applicable, they should be referred to therapy within the framework of clinical studies.


Asunto(s)
Quimioterapia del Cáncer por Perfusión Regional , Neoplasias Gastrointestinales/tratamiento farmacológico , Neoplasias Gastrointestinales/cirugía , Hipertermia Inducida/métodos , Neoplasias Peritoneales/secundario , Neoplasias Peritoneales/cirugía , Anciano , Instituciones Oncológicas , Quimioterapia Adyuvante , Colecistectomía , Colon Sigmoide/cirugía , Terapia Combinada , Femenino , Gastrectomía , Neoplasias Gastrointestinales/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Epiplón/cirugía , Selección de Paciente , Neoplasias Peritoneales/tratamiento farmacológico , Neoplasias Peritoneales/mortalidad , Peritoneo/cirugía , Pronóstico , Seudomixoma Peritoneal/tratamiento farmacológico , Seudomixoma Peritoneal/mortalidad , Seudomixoma Peritoneal/cirugía , Derivación y Consulta , Esplenectomía , Análisis de Supervivencia
9.
Transpl Immunol ; 20(1-2): 55-60, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18762258

RESUMEN

The induction of tolerance towards allogeneic solid organ grafts is one of the major goals in transplantation medicine. Mesenchymal stem cells (MSC) inhibit the immune response in vitro, and thus are promising candidate cells to promote acceptance of transplanted organs in vivo. Such novel approaches of tolerance induction are needed since, to date, graft acceptance can only be maintained through life-long treatment with unspecific immunosuppressants that are associated with toxic injury, opportunistic infections and malignancies. We demonstrate that donor-derived MSC induce long-term allograft acceptance in a rat heart transplantation model, when concurrently applied with a short course of low-dose mycophenolate. This tolerogenic effect of MSC is at least partially mediated by the expression of indoleamine 2,3-dioxygenase (IDO), demonstrated by the fact that blocking of IDO with 1-methyl tryptophan (1-MT) abrogates graft acceptance. Moreover we hypothesize that MSC interact with dendritic cells (DC) in vivo, because allogeneic MSC are rejected in the long-term but DC acquire a tolerogenic phenotype after applying MSC. In summary, we demonstrate that MSC constitute a promising tool for induction of non-responsiveness in solid organ transplantation that warrants further investigation in clinical trials.


Asunto(s)
Rechazo de Injerto/prevención & control , Supervivencia de Injerto/inmunología , Trasplante de Corazón , Terapia de Inmunosupresión/métodos , Inmunosupresores/administración & dosificación , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/inmunología , Ácido Micofenólico/análogos & derivados , Animales , Células Dendríticas/inmunología , Supervivencia de Injerto/efectos de los fármacos , Trasplante de Corazón/patología , Indolamina-Pirrol 2,3,-Dioxigenasa/antagonistas & inhibidores , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Células Madre Mesenquimatosas/efectos de los fármacos , Ácido Micofenólico/administración & dosificación , Ratas , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Triptófano/análogos & derivados , Triptófano/farmacología
10.
Dig Surg ; 25(3): 213-9, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18577867

RESUMEN

BACKGROUND: Intestinal ischemia is the prime vascular emergency for the visceral surgeon. However, the diagnosis of mesenteric ischemia is difficult, the surgical options are often limited and the overall outcome is generally poor. METHODS: We report on a single center series of 83 patients undergoing surgery for mesenteric ischemia during a 3-year period. Risk factors, clinical presentation, type and timing of imaging studies and their implications for surgical therapy and outcome are analyzed. RESULTS: Hypertension and diabetes were the most common risk factors (68/64% of all patients). Abdominal pain was the most general symptom upon presentation to the surgical unit (73%). Two-phase, contrast-enhanced computed tomography was applied as the standard preoperative imaging modality (correct diagnosis in 69%). Bowel resections were necessary in most patients; approaches to restore blood flow by vascular surgery interventions were applied in 17 patients (20%). The overall morbidity and mortality rate in our study cohort was expectedly high (59% 1 month mortality). CONCLUSION: The diagnosis and surgical treatment of mesenteric ischemia remains a major difficulty. We recommend preoperative CT analysis followed by an aggressive indication for early surgical exploration and bowel resection. An attempt of revascularization is justified for selected patients with limited macrovascular disease.


Asunto(s)
Isquemia , Mesenterio/irrigación sanguínea , Complicaciones Posoperatorias/etiología , Anciano , Femenino , Humanos , Isquemia/diagnóstico , Isquemia/etiología , Isquemia/cirugía , Masculino , Estudios Retrospectivos , Factores de Riesgo , Análisis de Supervivencia , Resultado del Tratamiento
11.
Chirurg ; 78(12): 1100, 1102-6, 1108-10, 2007 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-17992490

RESUMEN

Colorectal cancer is a common malignant disease with increasing incidence and a significant cause of death in cancer patients. More than 10% of patients with colorectal cancer show peritoneal carcinomatosis at initial diagnosis. Moreover, peritoneal metastasis is a common sign of recurrence. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are a new treatment strategy for highly selected patients with peritoneal carcinomatosis. Numerous studies show prolonged survival after CRS and HIPEC with acceptable morbidity and mortality rates. Accurate preoperative diagnostics and patient selection play a pivotal role in postoperative patient outcome. This promising treatment strategy is discussed regarding surgical technique, intraperitoneal chemotherapy, and patient outcome.


Asunto(s)
Quimioterapia del Cáncer por Perfusión Regional , Neoplasias Colorrectales/cirugía , Hipertermia Inducida , Neoplasias Peritoneales/secundario , Adulto , Anciano , Antineoplásicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Quimioterapia Adyuvante , Neoplasias Colorrectales/tratamiento farmacológico , Terapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Peritoneales/tratamiento farmacológico , Neoplasias Peritoneales/mortalidad , Neoplasias Peritoneales/cirugía , Pronóstico , Tasa de Supervivencia
12.
Int J Colorectal Dis ; 22(11): 1295-300, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17458551

RESUMEN

BACKGROUND: The presence of peritoneal carcinomatosis arising from colorectal cancer is associated with a poor prognosis. It was the purpose of this study to analyze morbidity, mortality, and survival after major cytoreductive surgery and intraperitoneal chemotherapy. MATERIALS AND METHODS: Thirty-two patients with peritoneal carcinomatosis were operated between April 2004 and June 2006 with the aim of complete macroscopical cytoreduction. All had a primary colorectal carcinoma. Surgery in these patients was followed by hyperthermic intraperitoneal chemotherapy (HIPEC) consisting of mitomycin C and doxorubicin. Data were analyzed retrospectively. RESULTS: Of all patients, 16 had appendix and 16 non-appendiceal colorectal carcinoma. A macroscopically complete cytoreduction was achieved in 24 patients by parietal and visceral peritonectomy procedures. All resections were combined with HIPEC. Overall morbidity was 34%. Most frequent surgical complications were intestinal obstruction (4/32), enteric fistula (2/32), pancreatitis (2/32), and bile leakage (2/32). One patient presented grade 4 renal toxicity. There was no hospital mortality. The median follow-up was 12 months. The 1-year overall survival rate is 96%. All patients after complete cytoreduction are still alive. CONCLUSIONS: Cytoreductive surgery combined with HIPEC is associated with an acceptable morbidity and low mortality. Complete cytoreduction may improve survival, particularly in well-selected patients having a low tumor volume and no extra-abdominal metastases.


Asunto(s)
Neoplasias Colorrectales/patología , Neoplasias Peritoneales/secundario , Neoplasias Peritoneales/terapia , Adulto , Anciano , Algoritmos , Ensayos Clínicos como Asunto , Terapia Combinada , Femenino , Alemania , Humanos , Hipertermia Inducida , Masculino , Persona de Mediana Edad , Epiplón/patología
13.
J Med Ethics ; 32(7): 389-894, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16816037

RESUMEN

BACKGROUND: Shortage of donor organs is one of the major problems for liver transplant programmes. Living liver donation is a possible alternative, which could increase the amount of donor organs available in the short term. OBJECTIVE: To assess the attitude towards living organ donation in the general population to have an overview of the overall attitude within Germany. METHODS: A representative quota of people was evaluated by a mail questionnaire (n = 250). This questionnaire had 24 questions assessing the willingness to be a living liver donor for different potential recipients. Factors for and against living liver donation were assessed. RESULTS: Donating a part of the liver was almost as accepted as donating a kidney. The readiness to donate was highest when participants were asked to donate for children. In an urgent life-threatening situation the will to donate was especially high, whereas it was lower in the case of recipient substance misuse. More women than men expressed a higher disposition to donate for their children. Sex, religion, state of health and age of the donor, however, did not influence other questions on the readiness to consider living organ donation. The will for postmortem organ donation positively correlated with the will to be a living organ donor. CONCLUSIONS: The motivation in different demographic subgroups to participate in living liver transplantation is described. Differences in donation readiness resulting from the situation of every donor and recipient are thoroughly outlined. The acceptance for a living liver donation was found to be high - and comparable to that of living kidney donation.


Asunto(s)
Trasplante de Hígado/psicología , Donadores Vivos/psicología , Obtención de Tejidos y Órganos/métodos , Actitud Frente a la Salud , Femenino , Alemania , Humanos , Trasplante de Riñón/psicología , Trasplante de Pulmón/psicología , Masculino , Persona de Mediana Edad , Motivación , Relaciones Padres-Hijo , Padres , Riesgo , Esposos , Encuestas y Cuestionarios
18.
J Virol ; 73(1): 140-51, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9847316

RESUMEN

Several compounds that specifically inhibited replication of the H1 and H2 subtypes of influenza virus type A were identified by screening a chemical library for antiviral activity. In single-cycle infections, the compounds inhibited virus-specific protein synthesis when added before or immediately after infection but were ineffective when added 30 min later, suggesting that an uncoating step was blocked. Sequencing of hemagglutinin (HA) genes of several independent mutant viruses resistant to the compounds revealed single amino acid changes that clustered in the stem region of the HA trimer in and near the HA2 fusion peptide. One of the compounds, an N-substituted piperidine, could be docked in a pocket in this region by computer-assisted molecular modeling. This compound blocked the fusogenic activity of HA, as evidenced by its inhibition of low-pH-induced cell-cell fusion in infected cell monolayers. An analog which was more effective than the parent compound in inhibiting virus replication was synthesized. It was also more effective in blocking other manifestations of the low-pH-induced conformational change in HA, including virus inactivation, virus-induced hemolysis of erythrocytes, and susceptibility of the HA to proteolytic degradation. Both compounds inhibited viral protein synthesis and replication more effectively in cells infected with a virus mutated in its M2 protein than with wild-type virus. The possible functional relationship between M2 and HA suggested by these results is discussed.


Asunto(s)
Antivirales/farmacología , Fusión Celular/efectos de los fármacos , Hemaglutininas Virales/efectos de los fármacos , Virus de la Influenza A/efectos de los fármacos , Replicación Viral/efectos de los fármacos , Amantadina/farmacología , Animales , Línea Celular , Clonación Molecular , Simulación por Computador , Concentración de Iones de Hidrógeno , Virus de la Influenza A/fisiología , Modelos Moleculares , Inhibidores de la Síntesis de la Proteína/farmacología , Proteínas Virales/biosíntesis
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