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BACKGROUND: Textbook outcome (TO) is a multidimensional quality management tool that uses a set of traditional surgical measures to reflect an "ideal" surgical result for a particular pathology. The aim of the present study is to record the rate of TO in patients undergoing elective surgery for colon cancer (CC). MATERIAL AND METHODS: Retrospective study of all patients undergoing scheduled CC surgery at a Spanish university hospital from September 2012 to August 2016. Patients with rectal cancer were excluded. The variables included in the definition of TO were: R0 resection, number of isolated nodes ≥ 12, no Clavien-Dindo ≥ IIIa complications, no prolonged stay, no readmissions, and no mortality in the first 30 days. The main objective of this study is to analyse the achievement of TO in these patients and to assess the relationship between TO and overall and disease-free survival. RESULTS: Five hundred and sixty-four patients were included in the study. TO was achieved in 49.8%. The sample had a mean age of 69 ± 11 years, and 60% were male. Female sex (OR 1.61; 95% CI 2.30-1.13), T3 and T4 classification (OR 2.50, 95% CI 4.59-1.36, and OR 2.55, 95% CI 5.21-1.24 respectively) and laparoscopic approach (OR 1.53, 95% CI 2.33-1.00) were independent factors that were significantly associated with achieving a TO. Patients who achieved TO had higher overall survival (p = 0.008) than those who did not. However, with regard to disease-free survival, no statistically significant differences were found (p = 0.303). CONCLUSION: TO is a useful, easy-to-interpret management tool for measuring oncological results and for predicting patient survival.
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Carcinoma , Neoplasias del Colon , Laparoscopía , Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Supervivencia sin Enfermedad , Resultado del Tratamiento , Estudios Retrospectivos , Laparoscopía/métodos , Neoplasias del Colon/patología , Carcinoma/cirugíaRESUMEN
BACKGROUND: Ambulatory or outpatient surgery is defined as surgery that does not require an overnight hospital stay. It offers patients both convenience and reduced costs. With the increased use of bariatric surgery, Extended L-shaped Lipo-brachioplasty is now frequently requested as a follow-up procedure. Although numerous studies have focused on its technique and outcomes, none have evaluated its acceptability as an outpatient procedure. This was the aim of this prospective study. PATIENTS AND METHODS: This study was performed between January 2016 and September 2019. All patients undergoing extended L-shaped Lipo-brachioplasty during that period were included and divided into two groups, according to the type of hospitalization. For both groups, we recorded the demographics, medical and surgical data, as well as any postoperative complications. In the outpatient group, we also recorded discharge failures at day 0. RESULTS: 75 patients were included in the study (40 outpatients, 35 hospitalizations). There were no significant differences between the two groups in terms of demographics, surgical data, or the incidence of complications. In the outpatient group, three patients could not be discharged the evening of the procedure and had to stay overnight. No readmissions or major complications were reported in this group. CONCLUSION: Our prospective study shows that outpatient Extended L-shaped Lipo-brachioplasty safely provides the same outcomes as those performed during traditional hospitalization. We believe that for eligible patients, it should routinely be performed as an outpatient procedure.
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Procedimientos Quirúrgicos Ambulatorios , Pacientes Ambulatorios , Hospitalización , Humanos , Tiempo de Internación , Complicaciones Posoperatorias/epidemiología , Estudios Prospectivos , Estudios RetrospectivosRESUMEN
BACKGROUND/AIM: Low dose rate brachytherapy has been used as salvage therapy for locally recurrent prostate cancer (PC) after primary external beam radiation therapy (EBRT), along with surgery and cryotherapy. All these techniques, in particular, when applied to the whole gland, involve a relatively high risk of toxicity and may worsen the patient's quality of life. Our aim is to evaluate the results of whole-gland salvage brachytherapy (SBT) after primary EBRT in terms of toxicity, functional outcomes, and efficacy. MATERIALS AND METHODS: We retrospectively reviewed clinical data on 19 patients consecutively treated with SBT at our institution between June 2012 and November 2015. Local recurrences were identified with 11C-choline positron emission tomography/computed tomography and pelvic magnetic resonance imaging after biochemical recurrence according to Phoenix criteria (prostate-specific antigen nadir + 2). Low dose rate brachytherapy was performed by 125I permanent seeds implantation to the whole prostate gland, with a prescription dose of 130 Gy. At the time of SBT, only 2 patients were receiving androgen deprivation therapy. Acute and late toxicities were recorded using the CTCAE 4.0 scoring system. Quality of life was assessed using IPSS (International Prostate Symptoms Score) and IIEF (International Index of Erectile Function) questionnaires at baseline and 6, 12, and 24 months after SBT, and the respective mean values were compared using Student t test. Biochemical relapse-free survival (BRFS) was also calculated. RESULTS: Median follow-up after SBT was 24 months. Of 19 patients, 2 patients experienced a G3 cystitis (10.2%) and 1 patient experienced a G4 proctitis (5.3%), respectively. Mean pre-SBT IPSS scores and 6, 12, and 24 months after SBT were 5.84, 10.22, 15.72, and 8.10, respectively. Mean pre-SBT IIEF scores and 6, 12, and 24 months after SBT were 8.42, 3.55, 7.89, and 6.40, respectively. At the time of analysis, only 2 patients showed a biochemical relapse (3-year BRFS 85.2%). The Student t test demonstrated a worsening of functional outcome 6 months and 1 year after treatment but a subsequent improvement 2 years after SBT. CONCLUSIONS: Salvage brachytherapy for recurrent PC after primary EBRT seems to be a feasible treatment for selected patients. Our series revealed a severe toxicity peak 6 months and 1 year after local re-treatment and then they decrease. Early BRFS rates are good. However, these are very preliminary results so further patient accrual, long-term follow-up, and prospective trials are needed in the future.
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During active surveillance at the Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT, Palermo, Italy) with the CARBA screening medium, five pairs of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae and Escherichia coli strains were isolated in each of five colonized patients. In each patient, lateral gene transfer was demonstrated by comparing K. pneumoniae and E. coli strains, both possessing KPC-3, Tn4401a and pKpQIL-IT elements. The isolates were found to be multiclonal by multilocus sequence typing (sequence type (ST) 512 related to ST258, and ST307 belonging to a clonal complex different from the habitual sequence clone ST258 isolated in Italy) and pulsed-field gel electrophoresis. The results of our study highlight the easy transfer of KPC among Enterobacteriaceae colonizing the human intestine, and the active and careful surveillance required to identify and prevent the spread of these multidrug-resistant microorganisms.
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Proteínas Bacterianas/genética , Infecciones por Enterobacteriaceae/microbiología , Escherichia coli/aislamiento & purificación , Klebsiella pneumoniae/aislamiento & purificación , beta-Lactamasas/genética , Proteínas Bacterianas/metabolismo , Infección Hospitalaria/microbiología , Infecciones por Enterobacteriaceae/clasificación , Escherichia coli/enzimología , Escherichia coli/genética , Transferencia de Gen Horizontal , Humanos , Italia , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Tipificación de Secuencias Multilocus , beta-Lactamasas/metabolismoRESUMEN
PURPOSE: Recursive partitioning analysis (RPA) is a prognostic index capable of predicting survival in patients with brain metastases. Histology of the primary tumour has only recently been introduced among the factors that could potentially affect the prognosis of these patients. The main purpose of this study was to analyse the impact of RPA in correlation with histology of the primary tumour in patients with brain metastases treated with hypofractionated radiotherapy. MATERIALS AND METHODS: A total of 382 patients were treated at the Department of Radiotherapy of Brescia University, and RPA classes were retrospectively assigned to all patients. Univariate and multivariate analyses were then performed to verify the role of the single prognostic variables, for the entire group and for each prognostic class, as well as in correlation with histology of the primary tumour. RESULTS: Most patients were classified as RPA prognostic class 2 (48%). The majority of patients was treated with a total dose of 30 Gy delivered in ten fractions, whereas the dose of 20 Gy in four or five fractions was primarily used in patients classified as RPA class 3. At univariate analysis, the main variable correlating with overall survival (OS) was RPA class (p=0.000). Uni- and multivariate analysis performed on RPA class 1 patients only confirmed the role of general performance status, number of metastases and total radiotherapy dose for predicting OS. In the group with the worst prognosis (RPA class 3), none of the variables had a statistically significant role in improving OS. Tumour histology and radiotherapy dose influence OS, even in RPA class 1 and 2 patients. CONCLUSIONS: This analysis confirms that RPA prognostic class is the factor that most predicts survival. Primary tumour histology helps determine prognosis, especially in RPA prognostic classes 1 and 2. As regards RPA class 3, no factor influences survival prognosis.
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Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundario , Irradiación Craneana/métodos , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Encefálicas/mortalidad , Fraccionamiento de la Dosis de Radiación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Modelos de Riesgos Proporcionales , Dosificación Radioterapéutica , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
AIM: Stage-IV differentiated thyroid cancer (DTC) patients may present elevated serum thyroglobulin (Tg) levels associated with positive [(131)I] whole-body-scan (WBS). Nevertheless some patients in whom WBS does not reveal new sites of disease show increased Tg levels. This finding prompts thorough restaging in order to exclude the presence of metastases unable to concentrate iodine. The aim of our study was to evaluate the impact of [(18)F]FDG-PET/CT in both the assessment of overall extent of the disease and the therapeutic management in a group of stage-IV DTC patients. METHODS: On suspicious of non-iodine concentrating additional metastases, 20 stage-IV DTC patients with increasing Tg levels and stable positive post-therapy WBS were enrolled. Conventional imaging (CI) procedures, including neck ultrasonography, bone-scintigraphy and computed tomography (CT) were performed before [(18)F]FDG-PET/CT. RESULTS: [(18)F]FDG-PET/CT was positive in 16 out of 20 patients (80%). In 9 patients (45%) [(18)F]FDG PET/CT detected a larger number of tumour recurrences/metastatic sites than WBS+CI. [(18)F]FDG PET/CT findings prompted modification of the management of 11 patients (55%), in whom surgery or external radiotherapy were eventually considered more appropriate than radioactive iodine therapy. These further therapies improved the quality of life in several patients but did not change their survival rate. CONCLUSION: Our results showed that [18F]FDG-PET/CT can detect new radioiodine-negative metastases in advanced DTC patients with unchanged positive WBS and increasing Tg levels. [(18)F]FDG-PET/CT may constitute a useful tool in the choice of the best therapeutic strategy in such difficult cases.
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Fluorodesoxiglucosa F18 , Radioisótopos de Yodo , Neoplasias de la Tiroides/diagnóstico por imagen , Adenocarcinoma Folicular/diagnóstico por imagen , Adenocarcinoma Folicular/secundario , Adenocarcinoma Papilar/diagnóstico por imagen , Adenocarcinoma Papilar/secundario , Anciano , Femenino , Radioisótopos de Flúor , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Tomografía de Emisión de Positrones , Radiofármacos , Estudios Retrospectivos , Tiroglobulina/sangre , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/terapia , Tomografía Computarizada por Rayos XRESUMEN
DESIGN: Recombinant human TSH-stimulated thyroglobulin (Tg) levels (rhTSH-Tg) are sufficient for early follow-up of low-risk differentiated thyroid cancer (DTC) patients after thyroidectomy and radioiodine (131I) remnant ablation (RAI). Serum Tg levels at the time of remnant ablation (ablation-Tg) is thought to be related with rhTSH-Tg and may be predictive of recurrent disease. During long-term follow-up, Tg levels on levo-T4 (L-T4) suppressive treatment (suppressive-Tg) is sufficiently sensitive to avoid further evaluations in patients with undetectable rhTSH-Tg. The aim of our study was to verify whether, in a subgroup of low-risk DTC patients, the association of low ablation-Tg levels (<10 microg/l) with undetectable suppressive-Tg concentrations has a sufficient negative predictive value (NPV) for recurrence of disease, leading to avoid rhTSH testing. METHODS: We enrolled 169 low-risk DTC patients treated by thyroidectomy + RAI and undetectable suppressive-Tg at 12-month followup. In all patients, we retrospectively evaluated ablation-Tg and rhTSH-Tg. For all patients, 2-yr follow-up was available. RESULTS: Based on rhTSH-Tg>2 microg/l, relapsing disease was histologically proven in 2 patients. rhTSH-Tg levels between 0.6-2.0 microg/l, with no evidence of disease, was observed in 10 patients (6%). One hundred and fifty-seven patients showed undetectable rhTSH-Tg. The NPV of undetectable suppressive- Tg was 92.8%. The ablation-Tg level was <10 microg/l in 140 patients. In this group, the NPV of undetectable suppressive- Tg was 100%. CONCLUSION: Our data indicate that undetectable suppressive-Tg value, combined with ablation- Tg levels <10 microg/l, may avoid a significant number of high-cost rhTSH-Tg test.
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Tiroglobulina/sangre , Tiroidectomía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Radioisótopos de Yodo/uso terapéutico , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Pronóstico , Proteínas Recombinantes , Neoplasias de la Tiroides/radioterapia , Neoplasias de la Tiroides/cirugía , Tirotropina , Tiroxina/uso terapéuticoRESUMEN
PURPOSE: The purpose of this article is to illustrate a case where acquisition of digital imaging know-how by a modern radiotherapy division has helped to solve a technical problem while allowing substantial savings through the use of free and open-source resources. The problem was related to the necessity to route, with complex policies, the images produced by different digital imaging and communications in medicine (DICOM) sources within the department or in other divisions and/or hospitals. MATERIALS AND METHODS: The problem was solved by using completely free, well-tested and stable technologies (PHP, Apache, MySQL, DCMTK OFFIS, Red Hat Linux 9A and Linux Fedora Core 4) and low-cost hardware to contain costs. In the development, we also considered integration of the routed images with the existing electronic clinical records. RESULTS: The system developed, called the dicom router, implemented two kinds of routing: manual and automatic, both oriented to link the images acquired with the existing electronic clinical records. System stability was enhanced in a second phase by using a low-cost hardware redundancy solution. The system has now been operating for 1 year and has proved the value of the technologies used. CONCLUSIONS: The need to operate with more than one provider creates a series of integration issues, so that it becomes economically appealing to acquire internally the knowledge needed to interact more precisely with providers of big information technology (IT) solutions. This need is well catered for by open-source technologies, which are well documented and available to everyone. By using them, in-house IT technicians are able to implement valuable technical solutions for small-to medium-sized informatization problems, which would otherwise remain unsolved except with great economic efforts.
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Redes de Comunicación de Computadores , Sistemas de Información Radiológica/organización & administración , Humanos , Almacenamiento y Recuperación de la Información , Sistemas de Información Radiológica/economía , Programas Informáticos , Integración de Sistemas , Interfaz Usuario-ComputadorRESUMEN
Mutation screening of the BRCA1 and BRCA2 genes in probands with familial breast/ovarian cancer has been greatly improved by the multiplex ligation-dependent probe amplification (MLPA) assay able to evidence gene rearrangements not detectable by standard screening methods. However, no criteria for selection of cases to be submitted to the MLPA test have been reported yet. We used the BRCAPro software for the selection of familial breast/ovarian cancer probands investigated with the MLPA approach after negative BRCA1/2 conventional mutation screening. One hundred and seventy-seven probands were investigated for germline BRCA1/2 mutations after assessment of genetic risk using BRCAPro. Probands were classified as BRCAPro positive (n = 67) when the carrier probability (CP) was >10% and as BRCAPro negative (n = 110), when the CP was <10%. Conventional mutational analyses of the BRCA1/2 genes and, in one case, of p53 identified 22 pathogenetic germline mutations, 12 in BRCA1, 9 in BRCA2 and 1 in p53, in 22/177 (12.4%) probands. All the mutations except one were detected in BRCAPro-positive patients. In the 46 BRCAPro-positive cases that resulted negative by BRCA1/2 mutation, screening analysis of rearrangements within BRCA1/2 by MLPA was carried out. Three patients with a very high CP showed BRCA1 deletions, consisting of deletions of exons 1-2 in two probands and of exon 24 in the third proband. In one case, the exons 1-2 deletion was shown to cosegregate with disease in the family. No BRCA2 rearrangements were detected, but one patient showed the 1100delC of the CHEK2 gene, whose probe is present in the BRCA2 kit. In our series, the highest carrier detection rate of mutation screening plus MLPA analysis (52.3%) was in patients with a BRCAPro CP >50%.
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Proteína BRCA1/genética , Tamización de Portadores Genéticos , Predisposición Genética a la Enfermedad , Eliminación de Secuencia , Programas Informáticos , Adulto , Anciano , Proteína BRCA1/análisis , Proteína BRCA1/metabolismo , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama Masculina/epidemiología , Neoplasias de la Mama Masculina/genética , Neoplasias de la Mama Masculina/metabolismo , Femenino , Tamización de Portadores Genéticos/métodos , Predisposición Genética a la Enfermedad/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Ováricas/epidemiología , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Linaje , Prevalencia , Neoplasias de la Próstata/epidemiología , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Factores de RiesgoRESUMEN
BACKGROUND: The frequency and the type of BRCA1 mutations vary widely and might have different geographic and ethnic distribution. Most of these alterations are generally found in isolated populations as a consequence of the founder effect. The object of this study was to determine whether 4843delC, a deleterious mutation of the BRCA1 gene, might be due to a founder effect originating in the Sicilian region of Italy. This mutation was described by us for the first time and identified in two unrelated Sicilian families with hereditary breast/ovarian cancer. The two families were from the same geographical area (south-western area of Palermo, Sicily). The homogeneity of the ethnic group of the two families and the Single Nucleotide Polymorphism (SNPs) analysis of probands led us to perform a study of the allelotype of the various members. PATIENTS AND METHODS: The analysis of the haplotype of the probands and of several family members was conducted by means of a study of the highly polymorphic microsatellites within or flanking the BRCA1 gene. RESULTS: This analysis revealed the presence of a common allele associated with the mutation. CONCLUSIONS: We therefore conclude that 4843delC of the BRCA1 gene is a possible founder mutation in the Sicilian population.
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Análisis Mutacional de ADN , Efecto Fundador , Eliminación de Gen , Genes BRCA1 , Neoplasias de la Mama/genética , Femenino , Haplotipos , Humanos , Masculino , Repeticiones de Microsatélite , Neoplasias Ováricas/genética , Linaje , SiciliaRESUMEN
BACKGROUND: Over 600 different pathogenic mutations have been identified in the BRCA1 gene. Nevertheless, numerous missense mutations of unknown biological function still exist. Understanding of biological significance of these mutations should help in genetic counselling to carriers and their families. PATIENTS AND METHODS: A total of 104 patients with breast and/or ovarian cancer whose genetic counselling answered the criteria of the American Society of Clinical Oncology (ASCO 2003), were prospectively screened for mutations in all coding exons of the BRCA1 gene by automatic direct sequencing. RESULTS: During these mutational screening procedures one case presented three mutations classified in the Breast Cancer Information Core Database as unknown variants. These were 655A/G found in exon 8 of BRCA1, 1575T/C and 1767A/C found in exon 11 of the same gene. The identification of the three unknown variants in the proband (16SIRIO) and in her mother and sister indicates that such alterations exist in cis. CONCLUSIONS: Our results suggest that the charge and stechiometry variations determined by the changes in the amino acids Y179C, F486L and N550H might produce an effect on the conformation of the protein and, consequently, on its function.
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Neoplasias de la Mama/genética , Genes BRCA1 , Mutación Missense , Adulto , Proteína BRCA1/química , Proteína BRCA1/genética , ADN de Neoplasias/genética , Exones , Salud de la Familia , Femenino , Asesoramiento Genético , Variación Genética , Mutación de Línea Germinal , Humanos , Neoplasias Ováricas/genética , Linaje , Estudios Prospectivos , Conformación Proteica , SiciliaAsunto(s)
Intestinos/irrigación sanguínea , Oclusión Vascular Mesentérica/diagnóstico por imagen , Enfermedad Aguda , Anciano , Humanos , Intestinos/patología , Isquemia/etiología , Masculino , Arteria Mesentérica Superior , Oclusión Vascular Mesentérica/complicaciones , Necrosis , Tomografía Computarizada por Rayos XRESUMEN
OBJECTIVE: To analyse relapse patterns, toxicity and second malignancy in patients with stage I pure germ cell testicular tumours, treated in 1970-1999. PATIENTS AND METHODS: In all, 487 patients received irradiation after surgery to the infra- (407, 83.5%) or infra- and supra-diaphragmatic volumes (80, 16.5%). Treatment-related toxicity was classified according to previous criteria and fertility investigated in 246 men. Second malignancies were identified by retrospective analysis of clinical records or telephone interviews in men who no longer needed a long-term follow-up. RESULTS: The 10-year overall survival was 97% (98% and 96%, respectively, for the aortic nodes only, or aortic and iliac nodes, i.e. the 'dog leg' field) and disease-free survival was 94%. Twenty-one patients relapsed (five with a true 'in-field' recurrence, nine progressed to the mediastinum, and seven had disseminated disease). Acute toxicity was mainly gastrointestinal, with 7.6% classified as grade II. In all, 73 men achieved paternity after irradiation; nine did not but had normal sperm. Second malignancies were diagnosed in 16 (3.3%) men. CONCLUSION: Para-aortic irradiation may be used safely in patients with stage I seminoma and undisturbed testicular drainage, with equivalent results to the 'dog-leg' group; these unrandomized data confirm the lower toxicity and equivalent survival rates of this treatment.
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Seminoma/radioterapia , Neoplasias Testiculares/radioterapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Seguimiento , Humanos , Infertilidad Masculina/etiología , Masculino , Persona de Mediana Edad , Neoplasias Primarias Secundarias/etiología , Radioterapia/efectos adversos , Estudios Retrospectivos , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
A new series of indazole-containing alpha(v)beta(3) integrin antagonists is described. Starting with lead compound 18a, variations in a number of structural features were explored with respect to inhibition of the binding of beta(3)-transfected 293 cells to fibrinogen and to selectivity for alpha(v)beta(3) over GPIIbIIIa, another RGD-binding integrin. Indazoles attached to a 2-aminopyridine or 2-aminoimidazole by a propylene linker at the indazole 1-position and to a diaminopropionate derivative via a 5-carboxylate amide provided the best potency with moderate selectivity. Several differences in the SAR of the diaminopropionate moiety were observed between this series and a series of isoxazoline-based selective GPIIbIIIa antagonists. Compound 34a (SM256) was a potent antagonist of alpha(v)beta(3) (IC(50) 2.3 nM) with 9-fold selectivity over GPIIbIIIa.
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Indazoles/síntesis química , Receptores de Vitronectina/antagonistas & inhibidores , Adhesión Celular/efectos de los fármacos , Línea Celular , Fibrinógeno/metabolismo , Humanos , Técnicas In Vitro , Indazoles/química , Indazoles/farmacología , Modelos Moleculares , Agregación Plaquetaria/efectos de los fármacos , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Relación Estructura-ActividadRESUMEN
Research plays a pivotal role in the oncology treatment continuum. As research moves from the academic arena into the community, the nurse practitioner is more likely to be faced with the challenge of enrolling and managing trial participants. This article addresses various issues related to breast cancer research and the management of trial participants.
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Neoplasias de la Mama/psicología , Neoplasias de la Mama/terapia , Ensayos Clínicos como Asunto , Selección de Paciente , Investigación/organización & administración , Neoplasias de la Mama/epidemiología , Femenino , Humanos , Consentimiento Informado , Internet , Enfermeras PracticantesRESUMEN
The suitability of rabbit prothrombin activation fragment F 1.2 as a marker for the activation of the coagulation system was tested. Monoclonal antibodies to rabbit F 1.2 were raised, and a competitive F 1.2 ELISA was developed. Within the detection limit of the ELISA, no increase in rabbit F 1.2 was detected upon recalcification of plasma, whereas human F 1.2 increased 1500-fold. The apparent lack of F 1.2 formation in rabbit serum was confirmed by immunoblotting analysis of endogenous and biotin-labeled prothrombin. Meizothrombin and the B-chain of thrombin were the only prothrombin fragments detectable. In contrast, labeled human prothrombin formed, in addition, prethrombin 2 and F 1.2 in both human and rabbit serum. In contrast, rabbit F 1.2 formation could be demonstrated using purified rabbit prothrombin and factor Xa. These observations raise the possibility that rabbit prothrombin is less susceptible than the human counterpart to factor Xa cleavage at the 271/272 peptide bond. Thus, the primary structure of rabbit prothrombin was deduced by cDNA sequencing. While the 320/321 Xa cleavage site giving rise to meizothrombin was identical in rabbit and human prothrombin, the flanking region of the 271/272 Xa sensitive site contained a six amino acid deletion in the rabbit sequence. Taken together, these observations suggest that the observed differences between human and rabbit prothrombin activation may be due to different susceptibilities of the two Xa cleavage sites rather than plasma or serum cofactor(s).