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1.
Bone Joint Res ; 5(9): 419-26, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27678328

RESUMEN

OBJECTIVES: Cement augmentation of pedicle screws could be used to improve screw stability, especially in osteoporotic vertebrae. However, little is known concerning the influence of different screw types and amount of cement applied. Therefore, the aim of this biomechanical in vitro study was to evaluate the effect of cement augmentation on the screw pull-out force in osteoporotic vertebrae, comparing different pedicle screws (solid and fenestrated) and cement volumes (0 mL, 1 mL or 3 mL). MATERIALS AND METHODS: A total of 54 osteoporotic human cadaver thoracic and lumbar vertebrae were instrumented with pedicle screws (uncemented, solid cemented or fenestrated cemented) and augmented with high-viscosity PMMA cement (0 mL, 1 mL or 3 mL). The insertion torque and bone mineral density were determined. Radiographs and CT scans were undertaken to evaluate cement distribution and cement leakage. Pull-out testing was performed with a material testing machine to measure failure load and stiffness. The paired t-test was used to compare the two screws within each vertebra. RESULTS: Mean failure load was significantly greater for fenestrated cemented screws (+622 N; p ⩽ 0.001) and solid cemented screws (+460 N; p ⩽ 0.001) than for uncemented screws. There was no significant difference between the solid and fenestrated cemented screws (p = 0.5). In the lower thoracic vertebrae, 1 mL cement was enough to significantly increase failure load, while 3 mL led to further significant improvement in the upper thoracic, lower thoracic and lumbar regions. CONCLUSION: Conventional, solid pedicle screws augmented with high-viscosity cement provided comparable screw stability in pull-out testing to that of sophisticated and more expensive fenestrated screws. In terms of cement volume, we recommend the use of at least 1 mL in the thoracic and 3 mL in the lumbar spine.Cite this article: C. I. Leichtle, A. Lorenz, S. Rothstock, J. Happel, F. Walter, T. Shiozawa, U. G. Leichtle. Pull-out strength of cemented solid versus fenestrated pedicle screws in osteoporotic vertebrae. Bone Joint Res 2016;5:419-426.

2.
Ann Anat ; 208: 212-216, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27476505

RESUMEN

INTRODUCTION: Student tutors in the dissection course are expected to meet high demands in their job, to fulfill these expectations they receive training. Combined tutor training is well accepted by tutors and tutees, however, it is not known how tutor training influences student learning. Deduced from the learning goals of the tutor training, a randomized, controlled, single-blinded study was set up with a quantitative cross-sectional analysis to compare student learning behavior. METHODS: A total of 197 medical students, coached either by ten trained or ten untrained tutors, were enlisted in the study. To assess the students' learning behavior we employed the LIST questionnaire. A common factor analysis was calculated to extract dimensions. Factor scores of the extracted dimensions were calculated for both groups to estimate differences in learning behavior. RESULTS: Factor analysis of the LIST questionnaire revealed eight factors explaining 47.57% of the overall variance. The eight factors comprise: deep learning, attention, learning organization, cooperative learning, time management, learning effort, superficial learning and learning environment. Comparing the factor scores of the extracted dimensions, students coached by trained tutors learned significantly more with their fellow students (factor score in cooperative learning 0.194 vs. -0.205, p<0.05), than students trained by untrained tutors. Students coached by trained tutors also tend to be better organized in their learning (factor score in learning organization 0.115 vs. -0.122, p=0.16). CONCLUSION: The learning behavior of students coached by trained tutors differs from the learning behavior of students coached by untrained tutors. Students coached by trained tutors learn significantly more often in teams than their colleagues and are better organized.


Asunto(s)
Anatomía/educación , Disección/estadística & datos numéricos , Evaluación Educacional/estadística & datos numéricos , Grupo Paritario , Estudiantes de Medicina/estadística & datos numéricos , Formación del Profesorado/estadística & datos numéricos , Adulto , Curriculum , Método Doble Ciego , Docentes/estadística & datos numéricos , Femenino , Alemania , Humanos , Masculino , Formación del Profesorado/métodos , Enseñanza , Adulto Joven
3.
Ann Anat ; 208: 208-211, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27497713

RESUMEN

INTRODUCTION: Medical professionalism is an increasingly important issue in medical education. The dissection course represents a profound experience for undergraduate medical students, which may be suitable to address competencies such as self-reflection and professional behavior. MATERIAL AND METHODS: Based on a needs assessment, a seminar on medical professionalism was developed to parallel the dissection course. The conceptual framework for the teaching intervention is experiential learning. Specific learning goals and an interview guideline were formulated. After a pilot run, peer-teaching was introduced. RESULTS: Over three terms (winter 2012/13, 2013/14, 2014/15), an average of 129 students voluntarily participated in the seminar, corresponding to 40% of the student cohort. The evaluation (n=38) shows a majority of students agreeing that the seminar offers support with this extraordinary situation in general and also that the seminar helps them to become first impressions on how to cope with death and dying in their later professional life as a doctor, and, that it also provides them the means to reflect upon their own coping mechanisms. CONCLUSION: Although not yet implemented as an obligatory course, the seminar is appreciated and positively evaluated. Medical professionalism is an implicit aspect of the dissection course. To emphasize its importance, a teaching intervention to explicitly discuss this topic is advisable.


Asunto(s)
Anatomía/educación , Anatomía/ética , Disección/educación , Disección/ética , Ética Médica/educación , Profesionalismo/educación , Curriculum , Disección/psicología , Alemania , Profesionalismo/ética , Enseñanza
4.
Osteoarthritis Cartilage ; 24(7): 1200-9, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26879798

RESUMEN

OBJECTIVES: Current repair procedures for articular cartilage (AC) cannot restore the tissue's original form and function because neither changes in its architectural blueprint throughout life nor the respective biological understanding is fully available. We asked whether two unique elements of human cartilage architecture, the chondrocyte-surrounding pericellular matrix (PCM) and the superficial chondrocyte spatial organization (SCSO) beneath the articular surface (AS) are congenital, stable or dynamic throughout life. We hypothesized that inducing chondrocyte proliferation in vitro impairs organization and PCM and induces an advanced osteoarthritis (OA)-like structural phenotype of human cartilage. METHODS: We recorded propidium-iodine-stained fetal and adult cartilage explants, arranged stages of organization into a sequence, and created a lifetime-summarizing SCSO model. To replicate the OA-associated dynamics revealed by our model, and to test our hypothesis, we transduced specifically early OA-explants with hFGF-2 for inducing proliferation. The PCM was examined using immuno- and auto-fluorescence, multiphoton second-harmonic-generation (SHG), and scanning electron microscopy (SEM). RESULTS: Spatial organization evolved from fetal homogeneity, peaked with adult string-like arrangements, but was completely lost in OA. Loss of organization included PCM perforation (local micro-fibrillar collagen intensity decrease) and destruction [regional collagen type VI (CollVI) signal weakness or absence]. Importantly, both loss of organization and PCM destruction were successfully recapitulated in FGF-2-transduced explants. CONCLUSION: Induced proliferation of spatially characterized early OA-chondrocytes within standardized explants recapitulated the full range of loss of SCSO and PCM destruction, introducing a novel in vitro methodology. This methodology induces a structural phenotype of human cartilage that is similar to advanced OA and potentially of significance and utility.


Asunto(s)
Osteoartritis , Cartílago Articular , Condrocitos , Matriz Extracelular , Factor 2 de Crecimiento de Fibroblastos , Humanos
5.
Hum Reprod ; 29(11): 2374-81, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25190724

RESUMEN

STUDY QUESTION: How are protamine deficiencies associated with sperm head morphology in subfertile men? SUMMARY ANSWER: The prevalence of morphological variations and large nuclear vacuoles was slightly higher in protamine-deficient spermatozoa than in non-deficient spermatozoa. WHAT IS KNOWN ALREADY: A protamine deficiency was previously reported to be associated with an abnormal sperm morphology; however, how they are related to each other remains unclear. This is further confounded by a number of protamine-deficient spermatozoa having a normal head morphology. STUDY DESIGN, SIZE, DURATION: This is a cross-sectional study, including 36 men diagnosed with male factor infertility or participating in an assisted reproduction program. To assess sperm head morphology, this study analyzed 2400 spermatozoa with a protamine deficiency and 2400 spermatozoa with a normal protamine status. An additional 21 men were analyzed to examine DNA fragmentation and its relationship with protamine deficiencies and sperm head morphologies. PARTICIPANTS/MATERIALS, SETTING, METHODS: The morphology of the sperm head was evaluated based on its shape, size and nuclear vacuoles at a magnification of >6000×. Using elliptic Fourier analysis, the shape was summarized into four numeric variables. The protamine status was evaluated with chromomycin A3 (CMA3). Sperm head size, vacuoles and shape were compared between protamine-deficient and non-deficient spermatozoa. DNA fragmentation was evaluated with the terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) assay. The percentages of protamine-deficient spermatozoa and DNA fragmentation were compared between spermatozoa with morphologically normal heads and those with abnormal heads. MAIN RESULTS AND THE ROLE OF CHANCE: Variations in head size (P < 0.0001) and shape (P < 0.0001) were significantly higher, with narrower (P < 0.001), more fan-shaped (P < 0.01) and more square-shaped forms (P < 0.001) in protamine-deficient spermatozoa than in non-deficient spermatozoa; however, the distribution of morphological variations markedly overlapped. Protamine deficiencies were more frequently observed in spermatozoa with large nuclear vacuoles than in those without them (32.0 ± 3.1 versus 39.4 ± 2.9%, P < 0.001). The percentage of protamine-deficient spermatozoa was significantly lower in spermatozoa with a normal head morphology than in those with an abnormal head morphology (25.4 ± 2.6 versus 38.0 ± 2.5%, P < 0.001). The percentage of DNA fragmentation was significantly higher in protamine-deficient spermatozoa than in non-deficient spermatozoa (11.3 ± 2.1 versus 1.6 ± 0.6%, P < 0.001), and was lower in spermatozoa with a normal head morphology than in those with an abnormal head morphology (2.6 ± 0.7 versus 6.4 ± 0.2%, P < 0.001). LIMITATIONS, REASONS FOR CAUTION: We were unable to discriminate the kind of protamines or quantify the extent of the protamine deficiency in spermatozoa using the CMA3 staining method. WIDER IMPLICATIONS OF THE FINDINGS: This study provided a novel insight into how abnormal protamination affects sperm head morphology as well as the relationship between sperm head morphology and its own molecular integrity. Our results will contribute to a deeper understanding of the benefits and limitations of the morphological selection of spermatozoa for ICSI. STUDY FUNDING/COMPETING INTERESTS: This study was supported by a JSPS Grant-in-Aid for the Encouragement of Scientists (25931009, 26931010). All authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER: N/A.


Asunto(s)
Infertilidad Masculina/patología , Protaminas/metabolismo , Espermatozoides/patología , Vacuolas/patología , Adulto , Forma de la Célula , Estudios Transversales , Fragmentación del ADN , Humanos , Infertilidad Masculina/metabolismo , Masculino , Persona de Mediana Edad , Cabeza del Espermatozoide/metabolismo , Cabeza del Espermatozoide/patología , Espermatozoides/metabolismo , Vacuolas/metabolismo
6.
Placenta ; 34(11): 1036-43, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23972287

RESUMEN

OBJECTIVES: The invasion of extravillous trophoblasts (EVTs) to the decidua and spiral arteries in early pregnancy is a crucial step for a successful pregnancy; however, its mechanisms are not fully understood. Lipocalin2 (LCN2), a multifunctional secretory protein known as neutrophil gelatinase-associated lipocalin (NGAL), reportedly enhanced invasiveness via the activation of matrix metalloproteinase-9 (MMP-9) in several cancer cells. In this study, the expression and function of LCN2 in early placenta were analyzed. METHODS: Early placental tissues between 7 and 10 weeks of gestation were obtained from normal pregnant women who underwent elective termination. The expression of LCN2 was examined using immunostaining and RT-PCR. EVTs isolated from these placental tissues and a choriocarcinoma cell line (JAR) were used to investigate the effects of LCN2 on proliferation, invasion potential, and MMP-9 activity under hypoxia using a WST-1 assay, Matrigel invasion assay, and gelatin gel zymography, respectively. RESULTS: The immunohistochemical expression of LCN2 was observed in the cytoplasm of EVTs, cytotrophoblasts and the decidua, but not in syncytiotrophoblasts. The addition of recombinant LCN2 did not affect proliferation, but enhanced the invasiveness (500 ng/mL, p < 0.01) and MMP-9 activity of primary cultured EVTs and JAR in a dose-dependent manner. Silencing LCN2 using shRNA reduced the invasiveness (p < 0.01) and MMP-9 activity of JAR. In addition, the hypoxic condition (2% O2) increased LCN2 expression (p < 0.01), MMP-9 activity, and invasive ability (p < 0.01). CONCLUSIONS: LCN2 was involved in the invasiveness of EVTs, especially under hypoxia, via increased MMP-9 activity.


Asunto(s)
Proteínas de Fase Aguda/metabolismo , Movimiento Celular , Regulación del Desarrollo de la Expresión Génica , Lipocalinas/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Placenta/metabolismo , Placentación , Proteínas Proto-Oncogénicas/metabolismo , Proteínas de Fase Aguda/antagonistas & inhibidores , Proteínas de Fase Aguda/genética , Hipoxia de la Célula , Línea Celular Tumoral , Proliferación Celular , Células Cultivadas , Coriocarcinoma/enzimología , Coriocarcinoma/metabolismo , Coriocarcinoma/patología , Decidua/citología , Decidua/metabolismo , Femenino , Silenciador del Gen , Humanos , Lipocalina 2 , Lipocalinas/antagonistas & inhibidores , Lipocalinas/genética , Metaloproteinasa 9 de la Matriz/química , Invasividad Neoplásica , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Placenta/citología , Placenta/enzimología , Embarazo , Primer Trimestre del Embarazo , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Trofoblastos/citología , Trofoblastos/enzimología , Trofoblastos/metabolismo , Neoplasias Uterinas/enzimología , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/patología
7.
Z Orthop Unfall ; 149(6): 659-67, 2011 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-21590660

RESUMEN

AIM: This study evaluated the image quality of two different cone beam CT scanners used in the operation theatre in pelvic trauma surgery in relation to their radiation dosage. Furthermore, the assumption that a higher dosage would result in better image quality was analysed by using the different acquisition scanner modes. MATERIAL AND METHODS: We scanned the acetabulum (n=4) and iliosacral joints (n=4) of two human cadavers with a conventional CT and with two mobile cone beam CT scanners (Siemens Arcadis Orbic 3D and Ziehm Vision Vario 3D). With the two cone beam CT scanners (3D-BV), we used 6 different acquisition modes with different radiation dosages. The axial views of all scans were exported and blinded. Subsequently, the images were evaluated by 7 medical doctors with regard to identifiability of cortical structures (acetabular joint, fovea capitis femoris, cortical bone of the femur head, iliosacral joint, and sacral foramina), and the quality of the cancellous structure of the femur head. The evaluation was performed on axial views by using a defined five-point score. The interrater quality was statistically analysed according to Cohen with the kappa coefficient. In addition, the Wilcoxon test was used to identify significances between the 21 paired results of the evaluators. For determination of the signal-to-noise ratio, a Catphan 600 reference block with two different test elements (Teflon, PMP) was used. RESULTS: Overall, the image quality of the conventional CT scans received the best score. Comparing the two 3D cone beams, the image quality of the Siemens Arcadis Orbic 3D in high-dosage mode received the best score (median: 2.40), the Ziehm Vision Vario 3D in low-dose mode without large patient key received the lowest score (median: 3.16). The differences in the 21 paired results of the two different acquisition modes were significant in 17 cases (p < 0.05) but the size of difference when comparing the different acquisition modes was almost always small. The interobserver agreement in one acquisition mode was low (kappa 0.008-0.134). The overall evaluation results of the same acquisition mode diverged by up to 2 score points. We noted a higher signal-to-noise ratio in the high dosage mode than in the low dosage mode. DISCUSSION: When using intraoperative 3D imaging with the cone beam CT technique for pelvic injury, image acquisition in low-dose mode is adequate in terms of signal-to-noise ratio and image quality. The image quality does not correlate linearly with a higher radiation dosage. Therefore, the pelvic trauma surgeon using this technique is encouraged to gather his own experience with low dose modes thereby reducing patient radiation exposure.


Asunto(s)
Tomografía Computarizada de Haz Cónico/instrumentación , Imagenología Tridimensional/instrumentación , Huesos Pélvicos/diagnóstico por imagen , Huesos Pélvicos/cirugía , Cirugía Asistida por Computador/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
8.
Ann Anat ; 192(6): 349-54, 2010 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-20947320

RESUMEN

Despite the rapid rise of integrated curricula, the teaching of gross anatomy by traditional dissection remains a central element in most medical programs worldwide. However, modern didactic concepts demand the integration of clinical content in preclinical settings. The implementation of interdisciplinary tools often leads to a reduction in teaching of comprehensive anatomy. 'Tübingen's Sectio chirurgica' (TSC) introduces a concept of a teaching activity in which surgical prosection is performed in addition to the traditional dissection course. TSC is designed to integrate clinical and preclinical content in a traditional medical curriculum without affecting the systematic presentation of anatomical content. In the past 2 years, about 10,000 medical students have participated in the use of telemedical transmissions of 'live surgery' in a total of 25 sessions of TSC. Here we describe the organisational plan of TSC and the results of an evaluation which was performed to monitor the influence of TSC on student motivation for surgical disciplines as well as for the learning of anatomical factual content. We demonstrate that additional surgical prosection is a valuable tool in increasing the coherence between preclinical and clinical parts of medical education programs.


Asunto(s)
Anatomía/educación , Disección/educación , Especialidades Quirúrgicas/educación , Enseñanza/métodos , Cadáver , Curriculum/normas , Curriculum/tendencias , Alemania , Humanos , Aprendizaje Basado en Problemas/normas , Aprendizaje Basado en Problemas/tendencias , Telemedicina , Comunicación por Videoconferencia
9.
Urologe A ; 48(8): 901-3, 2009 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-19458931

RESUMEN

After the surgical treatment of a recurrent enterocele and rectocele using a polypropylene implant, a patient developed a reversible paralysis. Haematoma was excluded. To search for the cause of the paralysis, polypropylene implants were inserted in four ethanol-preserved cadavers. Their dissection showed a safe distance at all points between the implant and the sciatic nerve. The patient's paralysis was most likely due to the lithotomy position, with an overstretching of the sciatic nerve during the intraoperative flexion of the hip joint.


Asunto(s)
Diafragma Pélvico/cirugía , Prótesis e Implantes/efectos adversos , Neuropatía Ciática/diagnóstico , Neuropatía Ciática/etiología , Diagnóstico Diferencial , Femenino , Hernia/complicaciones , Herniorrafia , Humanos , Persona de Mediana Edad , Neuropatía Ciática/prevención & control
10.
Eur J Surg Oncol ; 35(5): 552-6, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-18653307

RESUMEN

OBJECTIVE: The present anatomic study investigates alternative draining pathways of the petrosal vein territory, which allow compensation in case of surgical sacrifice. METHODS: In eight (four formaldehyde fixed and four alcohol fixed) specimens the petrosal vein complex has been dissected and studied. Three heads have been selectively injected via the superior petrous sinus with colored silicon in two different colors. Thereafter the posterior fossa content was removed epidurally from the skull and further fixed in 4% formaldehyde. The nervous and vascular structures were dissected under microscopic control, measured and photographed. 3D-photographs were elaborated. RESULTS: The petrosal vein was present in all cases and joined the superior petrous sinus always lateral to the trigeminal nerve as a single trunk. In the selectively injected specimens no passage of the colored silicon mixture to the contralateral venous brainstem territory could be discerned. However, the ipsilateral anastomoses to the deep supratentorial venous system--peduncular, anterolateral pontomesencephalic, lateral mesencephalic veins, and the tectal veins in connection with the pontotrigeminal vein--filled in all cases. CONCLUSION: Although the present anatomical model does not reflect physiological aspects of vascular dynamics, we document an apparently compensatory venous blood drainage occurring via anastomotic pathways directed to the ipsilateral supratentorial venous system. These findings represent an interesting aspect for preoperative image-guided planning in cerebello-pontine angle surgery.


Asunto(s)
Venas Cerebrales/anatomía & histología , Neoplasias del Tronco Encefálico/cirugía , Cadáver , Neoplasias Cerebelosas/cirugía , Humanos , Microcirugia , Procedimientos Neuroquirúrgicos , Hueso Petroso , Tomografía Computarizada por Rayos X
11.
Phys Med Biol ; 52(21): 6389-99, 2007 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-17951850

RESUMEN

This study investigated the temperature elevation in the eye of anatomically based human head models for plane-wave exposures. The finite-difference time-domain method is used for analyzing electromagnetic absorption and temperature elevation. The eyes in the anatomic models have average dimensions and weight. Computational results show that the ratio of maximum temperature in the lens to the eye-average SAR (named 'heating factor for the lens') is almost uniform (0.112-0.147 degrees C kg W(-1)) in the frequency region below 3 GHz. Above 3 GHz, this ratio increases gradually with an increase of frequency, which is attributed to the penetration depth of an electromagnetic wave. Particular attention is paid to the difference in the heating factor for the lens between this study and earlier works. Considering causes clarified in this study, compensated heating factors in all these studies are found to be in good agreement.


Asunto(s)
Cabeza/efectos de la radiación , Fantasmas de Imagen , Temperatura Corporal , Simulación por Computador , Femenino , Cabeza/patología , Calor , Humanos , Masculino , Modelos Anatómicos , Radiación , Dosis de Radiación , Radiometría , Programas Informáticos , Temperatura , Distribución Tisular
12.
Int J Gynecol Cancer ; 16(2): 610-4, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16681734

RESUMEN

Although the effectiveness of magnetic resonance imaging (MRI) in depicting cervical carcinoma has been reported, whether MRI can detect early-stage or stage IB "occult"-type cervical carcinoma remained undetermined. We examined the correlation between MRI and pathologic findings in 38 stage I (IB 28 cases, IA 10 cases) cervical carcinoma patients, with special reference to the influence of desmoplastic stromal reaction around the tumor. The results demonstrated that the tumor was detected by MRI in none of stage IA patients but in 21 (75%) stage IB patients. The image was clearly demonstrated in 15 of 18 (83%) tumors of more than 2 cm in diameter and in 6 of 10 (60%) tumors of 2 cm or less. The tumor image was evident in 21 of 22 (95%) tumors with prominent (>200 micron) stromal reaction but in none of 6 tumors with minimal (

Asunto(s)
Adenocarcinoma/diagnóstico , Carcinoma Adenoide Quístico/diagnóstico , Carcinoma de Células Escamosas/diagnóstico , Imagen por Resonancia Magnética , Neoplasias del Cuello Uterino/diagnóstico , Adulto , Anciano , Femenino , Humanos , Persona de Mediana Edad , Invasividad Neoplásica , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Cuidados Preoperatorios , Estudios Retrospectivos , Factores de Riesgo , Sensibilidad y Especificidad
13.
Eur J Clin Invest ; 33(11): 1006-12, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14636305

RESUMEN

BACKGROUND: Portal hypertension in cirrhosis is the result of increased intrahepatic vascular resistance to portal outflow as well as increased portal tributary blood flow. The angiotensin II type 1 receptor antagonist losartan has been suggested as a portal pressure-lowering drug in patients with cirrhosis. AIM: To investigate the systemic and splanchnic haemodynamic effects of different doses of losartan. METHODS: In 35 anaesthetized rats with secondary biliary cirrhosis, 3, 10 or 30 mg of losartan kg(-1) or solvent were administered intravenously. Ten sham-operated rats served as controls. Mean arterial pressure and portal pressure were measured by catheters in the femoral artery or portal vein. Systemic and splanchnic haemodynamics and mesenterico-systemic shunt rate were determined by the coloured microsphere method. RESULTS: Losartan reduced portal pressure (sham: 9.1 +/- 0.4. cirrhosis: 19.3 +/- 1.1, after 3 mg kg(-1) of losartan 16.4 +/- 0.4, after 10 mg kg(-1) of losartan 15.6 +/- 0.6, after 30 mg kg(-1) of losartan 14.9 +/- 0.6 mmHg) without reducing portal sinusoidal resistance. However, in cirrhotic rats it reduced portal tributary blood flow (sham: 4.3 +/- 0.6. cirrhosis: 8.6 +/- 1.4, after 3 mg kg(-1) of losartan 3.8 +/- 0.7, after 10 mg kg(-1) of losartan 4.7 +/- 0.5, after 30 mg kg(-1) of losartan 5.9 +/- 0.9 mmHg). This was owing either to an increase in splanchnic vascular resistance at the 3 mg kg(-1) dose or to a reduction in the splanchnic perfusion-pressure gradient secondary to a reduction in mean arterial pressure at the 10 and 30 mg kg(-1) doses (mean arterial pressure: sham: 109.7 +/- 4.8. cirrhosis: 109.4 +/- 2.8, after 3 mg kg(-1) of losartan 99.7 +/- 2.9, after 10 mg kg(-1) of losartan 89.9 +/- 3.4, after 30 mg kg(-1) of losartan 81.0 +/- 2.9 mmHg). CONCLUSIONS: Low doses of losartan reduce portal hypertension by an increase in splanchnic vascular resistance without hypotensive side-effects on arterial pressure.


Asunto(s)
Antihipertensivos/uso terapéutico , Hemodinámica/efectos de los fármacos , Hipertensión Portal/tratamiento farmacológico , Cirrosis Hepática Experimental/complicaciones , Losartán/uso terapéutico , Bloqueadores del Receptor Tipo 1 de Angiotensina II , Animales , Presión Sanguínea/efectos de los fármacos , Gasto Cardíaco/efectos de los fármacos , Hipertensión Portal/etiología , Hipertensión Portal/fisiopatología , Cirrosis Hepática Experimental/fisiopatología , Masculino , Microesferas , Presión Portal/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Circulación Esplácnica/efectos de los fármacos , Resistencia Vascular/efectos de los fármacos
14.
Int J Gynecol Cancer ; 13(1): 71-6, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12631224

RESUMEN

Brain metastases from endometrial carcinomas are rare and the treatment is usually difficult. Here, we report a patient with stage IV endometrial carcinoma whose brain metastases showed complete remission after stereotactic radiosurgery using a gamma-knife. A 48-year-old woman underwent removal of a single brain metastatic lesion, and one month later underwent hysterectomy for endometrioid-type G3, endometrial adenocarcinoma. After hysterectomy, a cranial magnetic resonance imaging (MRI) demonstrated multiple brain metastases and the patient received two courses of stereotactic radiosurgery and six courses of chemotherapy. Complete response of the brain lesions was obtained, and she is well without recurrence 38 months after the second stereotactic radiosurgery.


Asunto(s)
Adenocarcinoma/secundario , Adenocarcinoma/cirugía , Neoplasias Encefálicas/secundario , Neoplasias Encefálicas/cirugía , Neoplasias Endometriales/patología , Recurrencia Local de Neoplasia/cirugía , Radiocirugia , Adenocarcinoma/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Terapia Combinada , Neoplasias Endometriales/tratamiento farmacológico , Neoplasias Endometriales/cirugía , Femenino , Humanos , Histerectomía , Persona de Mediana Edad , Recurrencia Local de Neoplasia/tratamiento farmacológico , Inducción de Remisión
15.
Cancer ; 92(12): 3005-11, 2001 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-11753978

RESUMEN

BACKGROUND: Abnormality of cell cycle regulators and tumor suppressors, such as cyclin dependent kinase inhibitors (cdkIs), has been reported in malignant tumors. The current study was undertaken to examine the involvement of a cdkI, p27(Kip1) (p27), in the neoplastic process of the uterine cervical epithelium. METHODS: Immunohistochemical staining of p27 was performed in samples of normal cervical tissue (30 samples), cervical intraepithelial neoplasias (CINs; 17 samples), and invasive squamous cell carcinoma (SCC; 25 samples). The results were compared with the expression levels of Ki-67, cdk2, and cyclin E. The functional aspects of the p27 protein, such as its ability to bind to cdk2 and the phosphorylation activity of p27-bound cdk2, also were evaluated with an immunoprecipitation and histone H1 kinase assay. RESULTS: In normal cervical epithelia, the expression of p27 was strong in the intermediate and superficial cells but very weak in the parabasal cells. In CIN samples, the expression of p27 was negligible. The expression of p27 in these tissues showed an inverse topologic correlation to that of Ki-67, cdk2, and cyclin E. However, it is noteworthy that the number of p27 positive cells increased in SCC samples that also showed increased expression of Ki-67, cdk2, and cyclin E. The p27 protein in SCC samples was bound to cdk2 and cyclin E. However, cdk2 that was bound to p27 still possessed histone H1 kinase activity. CONCLUSIONS: The expression of p27 may be involved in the growth regulation of the normal squamous epithelium in the uterine cervix. However, aberrant function of p27 expression may occur in invasive SCC of the cervix.


Asunto(s)
Carcinoma de Células Escamosas/genética , Proteínas de Ciclo Celular/biosíntesis , Regulación Neoplásica de la Expresión Génica , Proteínas Supresoras de Tumor/biosíntesis , Displasia del Cuello del Útero/genética , Neoplasias del Cuello Uterino/genética , Carcinoma de Células Escamosas/patología , Proteínas de Ciclo Celular/análisis , Proteínas de Ciclo Celular/farmacología , Cuello del Útero/fisiología , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , Epitelio/fisiología , Femenino , Humanos , Inmunohistoquímica , Invasividad Neoplásica , Proteínas Supresoras de Tumor/análisis , Proteínas Supresoras de Tumor/farmacología , Neoplasias del Cuello Uterino/patología , Displasia del Cuello del Útero/patología
17.
Endocrinology ; 142(10): 4182-8, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11564672

RESUMEN

Progestins are known to suppress the growth of normal human endometrial glands and endometrial carcinomas possessing PRs. To elucidate the molecular mechanisms of progestin-induced growth inhibition, the expression and functional involvement of p27Kip1 (p27), a cyclin-dependent-kinase inhibitor, was investigated using cultured normal endometrial glandular cells and endometrial carcinoma cell lines (Ishikawa; PR-positive, KLE; PR-negative). Growth of the normal endometrial glandular cells and Ishikawa cells was suppressed by treatment with progesterone and medroxyprogesterone acetate, respectively, in association with an increase in p27 protein expression. Immunoprecipitation revealed that progestins accelerated the complex formation of p27 and cdk2 in both types of cells. However, treatment with progestins did not show any marked alterations in the mRNA expression of p27 in either normal glandular cells or Ishikawa cells. On the other hand, p27 protein degradation experiments indicated that treatment with progesterone and medroxyprogesterone acetate prolonged the degradation time of the normal endometrial glandular cells and Ishikawa cells, respectively. Forced expression of the p27 protein using a p27 expression plasmid reduced the growth activity of normal endometrial glandular cells. These findings suggest that p27 is functionally involved in progestin-induced growth suppression of normal and malignant endometrial epithelial cells and that up-regulation of the p27 protein by progestins possibly occurs via posttranslational mechanisms.


Asunto(s)
Proteínas de Ciclo Celular/fisiología , Neoplasias Endometriales/fisiopatología , Endometrio/fisiología , Neoplasias Glandulares y Epiteliales/fisiopatología , Proteínas Supresoras de Tumor , División Celular/efectos de los fármacos , División Celular/fisiología , Células Cultivadas , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , Neoplasias Endometriales/patología , Endometrio/citología , Femenino , Humanos , Neoplasias Glandulares y Epiteliales/patología , Progestinas/farmacología , Progestinas/fisiología , Regulación hacia Arriba/efectos de los fármacos
18.
Chemosphere ; 44(5): 973-9, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11513431

RESUMEN

Chlorinated derivatives of bisphenol A were detected in the final effluents of eight paper manufacturing plants in Shizuoka, Japan, where thermal paper and/or other printed paper is used as the raw material. Their amounts were determined by gas chromatography/mass spectrometry (GC/MS) after treatment with N, O-bis(trimethylsilyl)trifluoroacetamide, and ranged from traces to 2.0 microg/l. They are likely produced by chlorination of bisphenol A, which was released into the effluents from the pulping process of wastepaper, during or after bleaching with chlorine.


Asunto(s)
Conservación de los Recursos Naturales , Estrógenos no Esteroides/análisis , Fenoles/análisis , Eliminación de Residuos , Eliminación de Residuos Líquidos , Compuestos de Bencidrilo , Cloro/química , Monitoreo del Ambiente , Cromatografía de Gases y Espectrometría de Masas , Residuos Industriales , Papel , Purificación del Agua
19.
Mutat Res ; 492(1-2): 73-80, 2001 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-11377246

RESUMEN

We have previously isolated five mutagens in blue rayon-adsorbed substances from water at a site below sewage plants in the Nishitakase River, in Kyoto, Japan, and identified two of them as 2-phenylbenzotriazole derivatives, 2-[2-(acetylamino)-4-[bis(2-methoxyethyl)amino]-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-1) and 2-[2-(acetylamino)-4-[(2-cyanoethyl)ethylamino]-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-2). In the present study, we collected adsorbed materials on blue cotton (3 kg x 9 times) at the same location, and isolated a sufficient amount (97 microg) of one of the remaining three mutagens other than PBTA-1 and PBTA-2, for structural analysis, by multiple column chromatography. The structure of mutagen, accounting for 12% of the total mutagenicity of the blue rayon-adsorbed substances, was determined to be a PBTA-1 analogue, 2-[2-(acetylamino)-4-amino-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-4). PBTA-4 is a potent mutagen, inducing 190,000 and 7,800,000 revertants of Salmonella typhimurium TA98 and YG1024 per microgram, respectively, in the presence of S9 mix. In addition to the water of the Nishitakase River, PBTA-4 was detected in water samples from two rivers that flow through other regions where textile-dyeing industries have been developed. Like other PBTA analogues, PBTA-4 might also be produced from azo dyes during industrial processes in dyeing factories and treatment at sewage plants.


Asunto(s)
Compuestos Azo/análisis , Agua Dulce/química , Mutágenos/análisis , Triazoles/análisis , Animales , Cromatografía Líquida de Alta Presión , Colorantes/análisis , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Pruebas de Mutagenicidad , Mutágenos/toxicidad , Ratas , Ratas Sprague-Dawley , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Espectrofotometría Ultravioleta , Triazoles/síntesis química
20.
Mutat Res ; 470(2): 141-6, 2000 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-11027968

RESUMEN

Harman and norharman are widely distributed in the environment and consequently contaminate in domestic waste-water. It has been reported that they have co-mutagenic activity in the presence of non- mutagenic aromatic amines such as aniline and o-toluidine with S9 mix. When these beta-carbolines were treated with sodium hypochiorite under mild conditions, chlorinated derivatives were produced. Among them, 6-chloroharman and 6-chloronorharman showed much more potent co-mutagenic activities than harman and norharman in the presence of o-toluidine toward Salmonella typhimurium TA98 with S9 mix. These results suggest that the chlorination of harman and norharman occurs during disinfection at the sewage plant to produce potent co-mutagens that contaminate river water.


Asunto(s)
Harmina/análogos & derivados , Harmina/química , Mutágenos/toxicidad , Hipoclorito de Sodio/química , Biotransformación , Carbolinas , Harmina/toxicidad , Pruebas de Mutagenicidad , Mutágenos/química , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética
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