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1.
Sci Rep ; 12(1): 2907, 2022 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-35190584

RESUMEN

Physical activity (PA) helps prevention and aftercare of sporadic breast cancer (BC), cardiopulmonary fitness (CPF) being an age-independent predictor of tumor-specific mortality. Therefore, we wanted to identify predictors of CPF (represented by peak oxygen uptake: VO2peak) in BRCA1/2 mutation carriers whose risk of developing BC is high. We used cross-sectional data from 68 BRCA1/2 germline mutation carrying women participating in the randomized, prospective, controlled clinical study LIBRE-1. Assessments included cardiopulmonary exercise testing, medical and lifestyle history plus socioeconomic status. Additionally, the participants completed a psychological questionnaire regarding their attitude, subjective norms, perceived behavior control and intention towards PA. A multivariate logistic regression model was used to identify predictors for participants reaching their age- and sex-adjusted VO2peak reference values. 22 participants (median age: 40 years, interquartile range (IQR) 33-46) were cancer-unaffected and 46 cancer-affected (median age: 44 years, IQR 35-50). The strongest predictor for reaching the reference VO2peak value was attitude towards PA (Odds Ratio 3.0; 95% Confidence Interval 1.3-8.4; p = 0.021). None of the other predictors showed a significant association. A positive attitude towards PA seems to be associated with VO2peak, which should be considered in developing therapeutic and preventive strategies.Trial registrations: NCT02087592; DRKS00005736.


Asunto(s)
Actitud Frente a la Salud , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/prevención & control , Prueba de Esfuerzo , Ejercicio Físico/psicología , Mutación de Línea Germinal , Consumo de Oxígeno , Adulto , Neoplasias de la Mama/etiología , Neoplasias de la Mama/psicología , Estudios Transversales , Femenino , Heterocigoto , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Encuestas y Cuestionarios
2.
Rhinology ; 59(4): 402-404, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-34085061

RESUMEN

To the Editor: Monitoring of olfactory function and diagnosis of olfactory disorders using the pen-based "Sniffin' Sticks test" is problematic during the SARS-CoV-2 pandemic due to hygienic concerns. The aim of this study was to find out whether the results of olfactory testing obtained by presenting odours on a single-use filter paper is identical to performing the test by presenting the odour pens according to the manufacturer's manual.


Asunto(s)
COVID-19 , Trastornos del Olfato , Humanos , Odorantes , SARS-CoV-2 , Umbral Sensorial , Olfato
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2003-2006, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-33018396

RESUMEN

Breast-conserving surgery, also known as lumpectomy, is an early stage breast cancer treatment that aims to spare as much healthy breast tissue as possible. A risk associated with lumpectomy is the presence of cancer positive margins post operation. Surgical navigation has been shown to reduce cancer positive margins but requires manual segmentation of the tumor intraoperatively. In this paper, we propose an end-to-end solution for automatic contouring of breast tumor from intraoperative ultrasound images using two convolutional neural network architectures, the U-Net and residual U-Net. The networks are trained on annotated intraoperative breast ultrasound images and evaluated on the quality of predicted segmentations. This work brings us one step closer to providing surgeons with an automated surgical navigation system that helps reduce cancer-positive margins during lumpectomy.


Asunto(s)
Neoplasias de la Mama , Mastectomía Segmentaria , Mama/diagnóstico por imagen , Neoplasias de la Mama/diagnóstico por imagen , Femenino , Humanos , Redes Neurales de la Computación , Ultrasonografía Mamaria
4.
Addict Behav ; 100: 106126, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31605838

RESUMEN

Motivational processes like attentional bias and craving have been related to substance use. However, results are inconclusive. The present cross-sectional study was designed to replicate and extend previous research by investigating the relationships between attentional bias, craving, cognitive control and (severity of) cannabis use in a sample of inpatient adolescents and young adults (aged 18-30) diagnosed with CUD according to DSM-5. Contrary to expectations, our sample did not show attentional bias for cannabis words, neither did attentional bias correlate with craving, cognitive control or (severity of) cannabis use. In line with our hypotheses, however, increased session-induced craving was correlated to more daily cannabis use and reduced cognitive control. Furthermore, participants who displayed reduced cognitive control used more cannabis per day. A bootstrapped hierarchical regression model showed that, contrary to expectations, cognitive control did not modulate the relationships between attentional bias, craving and cannabis use. This study highlights the unique role of craving in relation to cannabis use and extends previous findings that cognitive control appears to have no moderating role regarding cannabis use disorder. Based on our results, it might well be that the underlying mechanisms of cannabis use disorder differ from those in other substance use disorders.


Asunto(s)
Sesgo Atencional , Cognición , Ansia , Abuso de Marihuana/psicología , Autocontrol/psicología , Adolescente , Adulto , Estudios Transversales , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Femenino , Humanos , Pacientes Internos/psicología , Masculino , Abuso de Marihuana/diagnóstico , Países Bajos/epidemiología , Test de Stroop , Adulto Joven
6.
Rhinology ; 58(2): 184-191, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-31693018

RESUMEN

BACKGROUND: The prevalence of olfactory impairment increases with age and is known to be an early sign of different neurodegenerative diseases. Only few population-based studies examined the prevalence of olfactory impairment and comparisons across studies are scarce. Aim of this analysis was to compare the prevalence and determinants of normosmia across five population based studies in Germany. METHODOLOGY: Data from five population-based, cross-sectional studies were included. They were independently conducted and used the same test system (Sniffin' Sticks Screening 12) to measure olfactory function. This system consists of 12 odor-dispensing felt-tip pens; the task is a forced-choice selection among four alternative odors per pen. Sociodemographic information and comorbidities were assessed in face-to-face interviews. Univariate, descriptive statistics and multivariable logistic regression models stratified by study, were performed to determine risks, i.e. prevalence odds ratios, associated with olfactory function. RESULTS: The prevalence of normosmic participants varied considerably across studies. Olfactory function was lower in men, decreased with age, and increased with higher education. Several individual comorbidities and a comorbidity index were associated with olfactory dysfunction. Recognition performance for three of the 12 pens was especially low in all studies. CONCLUSION: Four factors, well known to describe population composition, contribute to explain differences in the prevalence of olfactory function between studies when the same test system is used. Our results indicate that comorbidities and educational level should always be considered when test systems based on smell recognition are used in population-based studies.


Asunto(s)
Trastornos del Olfato , Olfato , Estudios Transversales , Alemania , Humanos , Masculino , Odorantes , Prevalencia , Factores de Riesgo
8.
IEEE Trans Biomed Eng ; 63(3): 600-6, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26302503

RESUMEN

OBJECTIVE: Lumpectomy, breast conserving tumor excision, is the standard surgical treatment in early stage breast cancer. A common problem with lumpectomy is that the tumor may not be completely excised, and additional surgery becomes necessary. We investigated if a surgical navigation system using intraoperative ultrasound improves the outcomes of lumpectomy and if such a system can be implemented in the clinical environment. METHODS: Position sensors were applied on the tumor localization needle, the ultrasound probe, and the cautery, and 3-D navigation views were generated using real-time tracking information. The system was tested against standard wire-localization procedures on phantom breast models by eight surgical residents. Clinical safety and feasibility was tested in six palpable tumor patients undergoing lumpectomy by two experienced surgical oncologists. RESULTS: Navigation resulted in significantly less tissue excised compared to control procedures (10.3 ± 4.4 versus 18.6 ± 8.7 g, p = 0.01) and lower number of tumor-positive margins (1/8 versus 4/8) in the phantom experiments. Excision-tumor distance was also more consistently outside the tumor margins with navigation in phantoms. The navigation system has been successfully integrated in an operating room, and user experience was rated positively by surgical oncologists. CONCLUSION: Electromagnetic navigation may improve the outcomes of lumpectomy by making the tumor excision more accurate. SIGNIFICANCE: Breast cancer is the most common cancer in women, and lumpectomy is its first choice treatment. Therefore, the improvement of lumpectomy outcomes has a significant impact on a large patient population.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/cirugía , Cirugía Asistida por Computador/métodos , Ultrasonografía/métodos , Mama/diagnóstico por imagen , Femenino , Humanos , Modelos Biológicos , Fantasmas de Imagen , Cirugía Asistida por Computador/instrumentación , Ultrasonografía/instrumentación
9.
Clin Biochem ; 49(3): 260-7, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26500002

RESUMEN

OBJECTIVES: Anti-Müllenria hormone (AMH) is an established biomarker for assessing ovarian reserve and predicting response to controlled ovarian stimulation. Its routine clinical use is hampered by the variability and low-throughput of available enzyme-linked immunosorbent assays (ELISA). The presented study examined if a fully automated AMH electrochemiluminescence assay (ECLIA; Elecsys® AMH assay, Roche Diagnostics) was suitable for measuring AMH levels in healthy women and in those diagnosed with polycystic ovary syndrome (PCOS). DESIGN AND METHODS: Five European laboratories evaluated the Elecsys® AMH assay independently under routine conditions over eight months. Within-run imprecision, repeatability, intermediate precision, linearity and functional sensitivity were assessed. The Elecsys® AMH assay was compared to a manual ELISA microtiter plate format test (AMH Gen II ELISA, modified version; Beckman Coulter Inc.) using 1729 routine serum samples. AMH reference intervals were determined in 887 healthy women with regular menstrual cycle aged 20­50 years, and 149 women diagnosed with PCOS. RESULTS: The fully automated Elecsys® AMH assay showed excellent precision, linearity, and functional sensitivity. The coefficient of variation was 1.8% for repeatability and 4.4% for intermediate precision. Values measured with the Elecsys® AMH assay were highly correlated with the manual ELISA method (modified version) but 24­28% lower. Reference intervals showed the expected AMH decline with age in healthy women and increased AMH levels in women with PCOS. CONCLUSIONS: The Elecsys® AMH assay demonstrated good precision under routine conditions, and is suitable for determining AMH levels in serum and lithium-heparin plasma.


Asunto(s)
Hormona Antimülleriana/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Mediciones Luminiscentes/métodos , Adolescente , Adulto , Hormona Antimülleriana/sangre , Automatización de Laboratorios/instrumentación , Automatización de Laboratorios/métodos , Biomarcadores/sangre , Ensayo de Inmunoadsorción Enzimática/normas , Femenino , Humanos , Laboratorios , Mediciones Luminiscentes/normas , Ciclo Menstrual/metabolismo , Persona de Mediana Edad , Síndrome del Ovario Poliquístico/sangre , Valores de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
10.
Interdiscip Perspect Infect Dis ; 2014: 708531, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25484896

RESUMEN

External ventricular drainage (EVD) is frequently used in neurosurgery to drain cerebrospinal fluid in patients with raised intracranial pressure. We performed a retrospective single center study in order to evaluate the incidence of EVD-related infections and to identify underlying risk factors. 246 EVDs were placed in 218 patients over a 30-month period. EVD was continued in median for 7 days (range 1-44). The cumulative incidence of EVD-related infections was 8.3% (95% CI, 5.3-12.7) with a device-associated infection rate of 10.4 per 1000 drainage days (95% CI, 6.2-16.5). The pathogens most commonly identified were coagulase-negative Staphylococcus (62%) followed by Enterococcus spp. (19%). Patients with an EVD-related infection had a significantly longer ICU (11 versus 21 days, P < 0.01) and hospital stay (20 versus 28.5 days, P < 0.01) than patients without. Median total duration of external drainage was twice as long in patients with EVD-related infection (6 versus 12 days, P < 0.01). However, there was no significant difference in the duration between first EVD placement and the occurrence of EVD-related infection and EVD removal in patients without EVD-related infection (6 versus 7 days, P = 0.87), respectively. Interestingly no risk factor for EVD-related infection could be identified in our cohort of patients.

11.
Anaesthesist ; 62(1): 27-33, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23319272

RESUMEN

BACKGROUND: Mortality in intensive care unit (ICU) patients is affected by multiple variables. The possible impact of the mode of ventilation has not yet been clarified; therefore, a secondary analysis of the "epidemiology of sepsis in Germany" study was performed. The aims were (1) to describe the ventilation strategies currently applied in clinical practice, (2) to analyze the association of the different modes of ventilation with mortality and (3) to investigate whether the ratio between arterial partial pressure of oxygen and inspired fraction of oxygen (PF ratio) and/or other respiratory variables are associated with mortality in septic patients needing ventilatory support. METHODS: A total of 454 ICUs in 310 randomly selected hospitals participated in this national prospective observational 1-day point prevalence of sepsis study including 415 patients with severe sepsis or septic shock according to the American College of Chest Physicians/Society of Critical Care Medicine criteria. RESULTS: Of the 415 patients, 331 required ventilatory support. Pressure controlled ventilation (PCV) was the most frequently used ventilatory mode (70.6 %) followed by assisted ventilation (AV 21.7 %) and volume controlled ventilation (VCV 7.7 %). Hospital mortality did not differ significantly among patients ventilated with PCV (57 %), VCV (71 %) or AV (51 %, p=0.23). A PF ratio equal or less than 300 mmHg was found in 83.2 % of invasively ventilated patients (n=316). In AV patients there was a clear trend to a higher PF ratio (204±70 mmHg) than in controlled ventilated patients (PCV 179±74 mmHg, VCV 175±75 mmHg, p=0.0551). Multiple regression analysis identified the tidal volume to pressure ratio (tidal volume divided by peak inspiratory airway pressure, odds ratio OR=0.94, 95 % confidence interval 95% CI=0.89-0.99), acute renal failure (OR=2.15, 95% CI=1.01-4.55) and acute physiology and chronic health evaluation (APACHE) II score (OR=1.09, 95% CI=1.03-1.15) but not the PF ratio (univariate analysis OR=0.998, 95 % CI=0.995-1.001) as independent risk factors for in-hospital mortality. CONCLUSIONS: This representative survey revealed that severe sepsis or septic shock was frequently associated with acute lung injury. Different ventilatory modes did not affect mortality. The tidal volume to inspiratory pressure ratio but not the PF ratio was independently associated with mortality.


Asunto(s)
Respiración Artificial/métodos , Sepsis/terapia , APACHE , Anciano , Intervalos de Confianza , Femenino , Alemania/epidemiología , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Oximetría , Estudios Prospectivos , Análisis de Regresión , Factores de Riesgo , Sepsis/epidemiología , Sepsis/mortalidad , Choque Séptico/terapia , Volumen de Ventilación Pulmonar
12.
J Air Waste Manag Assoc ; 63(12): 1457-68, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24558708

RESUMEN

Greenhouse gas (GHG) emissions from concentrated animal feeding operations vary by stage of production and management practices. The objective of this research was to study the effect of two dietary crude protein levels (12 and 16%) fed to beef steers in pens with or without corn stover bedding. Manure characteristics and GHG emissions were measured from feedlot pen surfaces. Sixteen equal-sized feedlot pens (19 x 23 m) were used. Eight were bedded approximately twice a week with corn stover and the remaining eight feedlot pens were not bedded. Angus steers (n = 138) were blocked by live weights (lighter and heavier) with 7 to 10 animals per pen. The trial was a 2 x 2 factorial design with factors of two protein levels and two bedding types (bedding vs. non bedding), with four replicates. The study was conducted from June through September and consisted of four -28-day periods. Manure from each pen was scrapped once every 28 days and composite manure samples from each pen were collected. Air samples from pen surfaces were sampled in Tedlar bags using a Vac-U-Chamber coupled with a portable wind tunnel and analyzed with a greenhouse gas gas chromatograph within 24 hr of sampling. The manure samples were analyzed for crude protein (CP), total nitrogen (TN), ammonia (NH3), total volatile fatty acid (TVFA), total carbon (TC), total phosphorus (TP), and potassium (K). The air samples were analyzed for methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) concentrations. The concentration of TN was significantly higher (p < 0.05) in manure from pens with cattle fed the high protein diets. The volatile fatty acids (VFAs) such as acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids concentrations were similar across both treatments. There were no significant differences in pen surface GHG emissions across manure management and dietary crude protein levels.


Asunto(s)
Alimentación Animal , Proteínas en la Dieta/administración & dosificación , Gases/análisis , Vivienda para Animales , Estiércol , Animales , Bovinos , Ácidos Grasos Volátiles/análisis , Efecto Invernadero , Tiempo (Meteorología)
13.
Clin Genet ; 82(5): 478-83, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21919902

RESUMEN

In families with clustering of breast and ovarian cancer, molecular testing of the major susceptibility genes BRCA1/2 helps to identify patients with disease mutations and healthy persons at high risk who can participate in targeted intervention programs. We investigated 5559 families from the German Consortium for Hereditary Breast and Ovarian Cancer included between 1997 and 2008 and treated under clinical routine conditions. In each family an index patient/person had been screened for deleterious mutations in BRCA1/2. Healthy relatives agreed to predictive testing in 888 of 1520 BRCA1/2 mutation-positive families (58%). Of 2646 eligible unaffected first-degree relatives 1143 decided to be tested (43%). In 325 families with BRCA1/2-positive index patients one related BC/OC patient was tested and 39 (12.0%; 95% confidence interval: 8.7-16.0%) discrepant cases found. A second related individual was screened in 163 of 3388 (4.9%) families with BRCA1/2-negative index patient and in eight families a BRCA1/2 mutation was found. In BRCA1/2 mutation-positive families, BC/OC patients lacking the familial mutation have to be expected at a rather high rate. In families with BRCA1/2-negative index patient we recommend a second screening if another patient with a high probability of carrying a BRCA1/2 mutation is available.


Asunto(s)
Proteína BRCA2/genética , Pruebas Genéticas , Ubiquitina-Proteína Ligasas/genética , Adulto , Anciano , Neoplasias de la Mama/genética , Femenino , Predisposición Genética a la Enfermedad , Alemania , Humanos , Persona de Mediana Edad , Mutación , Neoplasias Ováricas/genética , Linaje , Fenotipo , Factores de Riesgo
14.
Ultraschall Med ; 33(2): 141-5, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21104601

RESUMEN

PURPOSE: Ultrasound is a widely used diagnostic tool. In medical education, it can be used to teach sonographic anatomy as well as the basics of ultrasound diagnostics. Some medical schools have begun implementing student tutor-led teaching sessions in sonographic abdominal anatomy in order to meet the growing demand in ultrasound teaching. However, while this teaching concept has proven to be feasible and well accepted, there is limited data regarding its effectiveness. We investigated whether student tutors teach sonographic anatomy as effectively as faculty staff sonographers. MATERIALS AND METHODS: 50 medical students were randomly assigned to one of two groups. 46 of these could be included in the analysis. One group was taught by student tutors (ST) and the other by a faculty staff sonographer (FS). Using a pre/post-test design, students were required to locate and label 15 different abdominal structures. They printed out three pictures in three minutes and subsequently labeled the structures they were able to identify. The pictures were then rated by two blinded faculty staff sonographers. A mean difference of one point in the improvement of correctly identified abdominal structures between the pre-test and post-test among the two groups was regarded as equivalent. RESULTS: In the pre-test, the ST (FS) correctly identified 1.6 ± 1.0 (2.0 ± 1.1) structures. Both the ST and FS group showed improvement in the post-test, correctly identifying 7.8 ± 2.8 vs. 8.9 ± 2.9 structures, respectively (p < .0001 each). Comparing the improvement of the ST (6.2 ± 2.8 structures) versus the FS (6.9 ± 3.2) showed equivalent results between the two groups (p < .05 testing for equivalence). CONCLUSION: Basic abdominal sonographic anatomy can be taught effectively by student tutors.


Asunto(s)
Abdomen/diagnóstico por imagen , Anatomía Transversal/educación , Educación de Pregrado en Medicina , Docentes Médicos , Grupo Paritario , Estudiantes de Medicina , Ultrasonografía , Adulto , Actitud del Personal de Salud , Benchmarking , Competencia Clínica , Femenino , Alemania , Humanos , Masculino , Mentores , Estudios Prospectivos
15.
Fam Cancer ; 9(2): 109-15, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19763885

RESUMEN

Familial colorectal cancer (CRC) accounts for 10-15% of all CRCs. In about 5% of all cases, CRC is associated with a highly penetrant dominant inherited syndrome. The most common inherited form of non-polyposis CRC is the Lynch syndrome which is responsible for about 2-4% of all cases. Surveillance of individuals at high risk for CRC prevents the development of advanced CRC. About 1 million individuals in Western Europe are at risk for Lynch syndrome. We performed a survey to evaluate the strategies currently used to identify individuals at high risk for CRC in 14 Western European countries. Questionnaires were distributed amongst members of a European collaborative group of experts that aims to improve the prognosis of families with hereditary CRC. The survey showed that in all countries obtaining a family history followed by referral to clinical genetics centres of suspected cases was the main strategy to identify familial and hereditary CRC. In five out of seven countries with a (regional or national) CRC population screening program, attention was paid in the program to the detection of familial CRC. In only one country were special campaigns organized to increase the awareness of familial CRC among the general population. In almost all countries, the family history is assessed when a patient visits a general practitioner or hospital. However, the quality of family history taking was felt to be rather poor. Microsatellite instability testing (MSI) or immunohistochemical analysis (IHC) of CRC are usually recommended as tools to select high-risk patients for genetic testing and are performed in most countries in patients suspected of Lynch syndrome. In one country, IHC was recommended in all new cases of CRC. In most countries there are no specific programs on cancer genetics in the teaching curriculum for medical doctors. In conclusion, the outcome of this survey and the discussions within an European expert group may be used to improve the strategies to identify individuals at high risk of CRC. More attention should be given to increasing the awareness of the general population of hereditary CRC. Immunohistochemical analysis or MSI-analysis of all CRCs may be an effective tool for identifying all Lynch syndrome families. The cost-effectiveness of this approach should be further evaluated. All countries with a CRC population screening program should obtain a full family history as part of patient assessment.


Asunto(s)
Neoplasias Colorrectales Hereditarias sin Poliposis/diagnóstico , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales Hereditarias sin Poliposis/epidemiología , Reparación de la Incompatibilidad de ADN , Europa (Continente)/epidemiología , Asesoramiento Genético , Predisposición Genética a la Enfermedad , Pruebas Genéticas , Directrices para la Planificación en Salud , Humanos , Anamnesis , Proteína 2 Homóloga a MutS/genética , Mutación , Linaje , Factores de Riesgo
16.
Cell Prolif ; 42(6): 823-37, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19780759

RESUMEN

OBJECTIVES: This study aims to compare pharmacokinetics and pharmacodynamics of pegfilgrastim, a pharmaceutical recombinant human granulocyte colony-stimulating factor (rhG-CSF), with that of a newly developed reagent, Maxy-G34. This comparison was performed using rat experiments and biomathematical modelling of granulopoiesis. METHODS: Healthy rats and those with cyclophosphamide-induced neutropenia were treated with either pegfilgrastim or Maxy-G34 under various schedules. Time courses of absolute neutrophil count (ANC) and G-CSF serum level were measured and we constructed a combined pharmacokinetic/pharmacodynamic model of both drugs. Neutropenic episodes were assessed by experimental data and model simulations. RESULTS: Both Pegfilgrastim and Maxy-G34 showed strong dose-dependent efficacy in reducing neutropenic episodes. However, time courses of ANC and G-CSF serum levels were markedly different. The biomathematical model showed good agreement with these data. We estimated that differences between the two drugs could be explained by lower bioavailability and reduced elimination of Maxy-G34. Based on the data and model interpolations, we estimated that Maxy-G34 is superior in reducing neutropenic episodes. Also, we predicted that G-CSF administration 48 h after cyclophosphamide would be superior to its administration after 2 or 24 h, for both derivatives. CONCLUSION: Maxy-G34 is a highly potent drug for stimulation of neutrophil production in rats. By our modelling approach, we quantified differences between Maxy-G34 and pegfilgrastim, related to pharmacokinetic parameters. Model simulations can be used to estimate optimal dosing and timing options in the present preclinical rat model.


Asunto(s)
Factor Estimulante de Colonias de Granulocitos/farmacología , Factor Estimulante de Colonias de Granulocitos/farmacocinética , Modelos Biológicos , Polietilenglicoles/farmacología , Polietilenglicoles/farmacocinética , Animales , Antineoplásicos/efectos adversos , Ciclofosfamida/efectos adversos , Filgrastim , Factor Estimulante de Colonias de Granulocitos/uso terapéutico , Humanos , Masculino , Neutropenia/inducido químicamente , Neutropenia/tratamiento farmacológico , Polietilenglicoles/uso terapéutico , Ratas , Ratas Sprague-Dawley , Proteínas Recombinantes
17.
Cell Prolif ; 42(6): 813-22, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19689472

RESUMEN

OBJECTIVES: Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is widely used as treatment for granulocytopaenia during cytotoxic chemotherapy; however, optimal scheduling of this pharmaceutical is unknown. Biomathematical models can help to pre-select optimal application schedules but precise pharmacokinetic properties of the pharmaceuticals are required at first. In this study, we have aimed to construct a pharmacokinetic model of G-CSF derivatives filgrastim and pegfilgrastim in mice. METHODS: Healthy CD-1 mice and those with cyclophosphamide-induced granulocytopaenia were studied after administration of filgrastim and pegfilgrastim in different dosing and timing schedules. Close meshed time series of granulocytes and G-CSF plasma concentrations were determined. An ordinary differential equations model of pharmacokinetics was constructed on the basis of known mechanisms of drug distribution and degradation. RESULTS: Predictions of the model fit well with all experimental data for both filgrastim and pegfilgrastim. We obtained a unique parameter setting for all experimental scenarios. Differences in pharmacokinetics between filgrastim and pegfilgrastim can be explained by different estimates of model parameters rather than by different model mechanisms. Parameter estimates with respect to distribution and clearance of the drug derivatives are in agreement with qualitative experimental results. CONCLUSION: Dynamics of filgrastim and pegfilgrastim plasma levels can be explained by the same pharmacokinetic model but different model parameters. Beause of a strong clearance mechanism mediated by granulocytes, granulocytotic and granulocytopaenic conditions must be studied simultaneously to construct a reliable model. The pharmacokinetic model will be extended to a murine model of granulopoiesis under chemotherapy and G-CSF application.


Asunto(s)
Agranulocitosis/inducido químicamente , Antineoplásicos/efectos adversos , Ciclofosfamida/efectos adversos , Modelos Animales de Enfermedad , Factor Estimulante de Colonias de Granulocitos/farmacocinética , Modelos Biológicos , Animales , Filgrastim , Ratones , Polietilenglicoles , Proteínas Recombinantes
18.
Virchows Arch ; 454(5): 519-24, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19381686

RESUMEN

BRCA1-associated breast cancer frequently presents with estrogen-receptor (ERalpha) and progesterone-receptor (PR) negativity, grade 3, and early onset. In contrast, in BRCA1-deficient mice, ERalpha is highly expressed in early tumorigenesis. In a retrospective cohort study on 587 breast cancer patients with deleterious BRCA1 mutations, the correlation of ER, PR status, grading, age of onset, and tumor size was investigated. ERalpha and PR expression decreased from 62% in ductal carcinoma in situ (DCIS) to 20% and 16% in pT3, respectively (p value for ER 0.025 and PR 0.035, Fisher's exact test). The percentage of grade 1/2 tumors decreased from 44% in DCIS to 17% in pT3 (p value 0.074). Moreover, ER/PR positivity increased with increasing age. Our data suggest that early stage BRCA1-associated breast cancers are more frequently ERalpha and PR positive and low grade than advanced stages.


Asunto(s)
Proteína BRCA1/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Carcinoma Intraductal no Infiltrante/genética , Carcinoma Intraductal no Infiltrante/metabolismo , Receptor alfa de Estrógeno/metabolismo , Mutación , Receptores de Progesterona/metabolismo , Adulto , Edad de Inicio , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Carcinoma Intraductal no Infiltrante/patología , Femenino , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
19.
Bone Marrow Transplant ; 43(7): 553-61, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19079316

RESUMEN

We compared the efficacy and safety of empirical plus PCR-based vs empirical liposomal amphotericin B treatment after Allo-SCT. Allo-SCT recipients were randomized to receive either PCR-based preemptive therapy (group A; n=198) or empirical antifungal therapy (group B; n=211) with liposomal amphotericin B. In group A, therapy was started after one positive PCR result or after 120 h of febrile neutropenia refractory to broad-spectrum antibacterial therapy. In group B, liposomal amphotericin B was started after 120 h of refractory febrile neutropenia. Demographic and clinical characteristics were well balanced. A total of 112 (57.1%) patients in group A and 76 (36.7%) patients in group B received antifungal therapy (P<0.0001). Twelve patients in group A and 16 patients in group B developed proven invasive fungal infection (IFI). Survival curves showed better survival until day 30 when close PCR monitoring was performed (mortality 1.5 vs 6.3%; P=0.015), but there was no difference at day 100. At day 100, no difference was observed in the incidence of IFI (primary end point) and survival between the two arms. Further studies are required to assess the benefit of using PCR in patients after SCT.


Asunto(s)
Anfotericina B/uso terapéutico , Micosis/tratamiento farmacológico , Trasplante de Células Madre , Adolescente , Adulto , Anciano , Anfotericina B/efectos adversos , Niño , Preescolar , Femenino , Humanos , Lactante , Liposomas/uso terapéutico , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Trasplante de Células Madre/efectos adversos , Análisis de Supervivencia , Trasplante Homólogo
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