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1.
Ann Oncol ; 28(11): 2874-2881, 2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-28945875

RESUMEN

BACKGROUND: The European Organization for Research and Treatment of Cancer (EORTC) QLQ-LC13 was the first module to be used in conjunction with the core questionnaire, the QLQ-C30. Since the publication of the LC13 in 1994, major advances have occurred in the treatment of lung cancer. Given this, an update of the EORTC QLQ-LC13 was undertaken. METHODS: The study followed phases I to III of the EORTC Module Development Guidelines. Phase I generated relevant quality-of-life issues using a mix of sources including the involvement of 108 lung cancer patients. Phase II transformed issues into questionnaire items. In an international multicenter study (phase III), patients completed both the EORTC QLQ-C30 and the 48-item provisional lung cancer module generated in phases I and II. Patients rated each of the items regarding relevance, comprehensibility, and acceptance. Patient ratings were assessed against a set of prespecified statistical criteria. Descriptive statistics and basic psychometric analyses were carried out. RESULTS: The phase III study enrolled 200 patients with histologically confirmed lung cancer from 12 centers in nine countries (Cyprus, Germany, Italy, Israel, Spain, Norway, Poland, Taiwan, and the UK). Mean age was 64 years (39 - 91), 59% of the patients were male, 82% had non-small-cell lung cancer, and 56% were treated with palliative intent. Twenty-nine of the 48 questions met the criteria for inclusion. CONCLUSIONS: The resulting module with 29 questions, thus currently named EORTC QLQ-LC29, retained 12 of the 13 original items, supplemented with 17 items that primarily assess treatment side-effects of traditional and newer therapies.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/terapia , Neoplasias Pulmonares/terapia , Calidad de Vida , Carcinoma Pulmonar de Células Pequeñas/terapia , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Pulmón de Células no Pequeñas/complicaciones , Carcinoma de Pulmón de Células no Pequeñas/psicología , Terapia Combinada , Europa (Continente) , Femenino , Estudios de Seguimiento , Indicadores de Salud , Humanos , Agencias Internacionales , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/psicología , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Carcinoma Pulmonar de Células Pequeñas/complicaciones , Carcinoma Pulmonar de Células Pequeñas/psicología , Encuestas y Cuestionarios , Resultado del Tratamiento
2.
Oper Dent ; 46(3): E132-E157, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-34370019

RESUMEN

OBJECTIVES: This systematic review of in vitro studies investigated the influence of the post-space treatment used to remove the smear layer on the bond strength of the post to root canal dentin. METHODS AND MATERIALS: In vitro studies included in this study were identified from PubMed/MEDLINE, Lilacs, and Scopus databases up until March 2019, without limits on publication year or language. Two reviewers independently selected the studies based on the inclusion and exclusion criteria, extracted the data, and evaluated the risk of bias of all studies. A random effects model was used for pairwise meta-analyses (control vs. post-space preparation groups) at a significance level of p<0.05. RESULTS: Of the 2,832 potentially eligible studies, 453 studies were selected for full-text analysis, and 75 were included in this systematic review. Only one study was considered to have a low risk of bias. Overall, post-space treatment significantly improves the bond strength to root canal dentin (p<0.00001). CONCLUSION: Post-space treatment has a positive influence on the bond strength of the post to root canal dentin. In this review, the post-space treatments that improve the adhesive resistance of the post were ethanol, sodium hypochlorite, and ethylene diamine tetra-acetic acid (NaOCl + EDTA), NaOCl + EDTA + ultrasound, erbium-doped yttrium aluminium garnet laser (Er:YAG laser), neodymium-doped yttrium aluminium garnet laser (Nd:YAG laser), and diode laser.


Asunto(s)
Láseres de Estado Sólido , Capa de Barro Dentinario , Diente no Vital , Dentina , Humanos , Preparación del Conducto Radicular
3.
Oper Dent ; 45(4): E185-E195, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32216727

RESUMEN

CLINICAL RELEVANCE: When luting relined fiber posts with self-adhesive cement, the surface treatment of the posts influences the adhesion of the fiber posts to root dentin. SUMMARY: This study evaluated the effect of surface treatment and silanization of resin composite on the bond strength of relined fiber posts cemented with self-adhesive resin cement. Push-out and microtensile bond strength (MTBS) tests were performed in this study. The endodontic treatment of 80 single-rooted bovine teeth was first performed in the push- out test segment, followed by weakening the intracanal walls by diamond bur. Then, the glass fiber posts were adapted with resin composite to fill the root canals, followed by photoactivation and resin surface conditioning according to four different experimental conditions: no conditioning as control, 10% hydrofluoric acid, 35% hydrogen peroxide, or air abrasion with alumina particle (all groups were subdivided into "with silanization" or "without silanization," thus totaling eight experimental groups). Self-adhesive resin cement was used for the post cementation. Four slices per tooth were obtained for the push-out tests. Next, 160 blocks of resin composite were first produced for the MTBS tests; their bonding surfaces were conditioned (as mentioned, ie, eight treatments), and they were cemented to each other. The 80 sets (n=10/treatment) were then cut into microbars (16/set): eight were immediately tested, while the other eight were thermocycled (12,000×) and stored (120 days) before MTBS. Failure modes and topographic analyses were performed after treatments. There was no statistically significant difference for the push-out results. In MTBS, surface treatment and silanization had a significant effect (p<0.001). Aging decreased bond strength for all groups. Considering the aged groups, air abrasion promoted the highest values and silanization improved bond strength for all treatments except air abrasion. The alumina particle air abrasion of the relining resin composite promoted the highest bond strengths when luting with self-adhesive resin cement.


Asunto(s)
Recubrimiento Dental Adhesivo , Técnica de Perno Muñón , Abrasión Dental por Aire , Animales , Bovinos , Resinas Compuestas , Cementos Dentales , Vidrio , Ensayo de Materiales , Cementos de Resina , Propiedades de Superficie
4.
Oper Dent ; 44(6): E299-E308, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31283420

RESUMEN

PURPOSE: To investigate the influence of ferrule thickness on fracture resistance after mechanical cycling of teeth restored with different intracanal posts. METHODS AND MATERIALS: One hundred twenty bovine incisor teeth were randomized into six study groups, based on the intracanal post used (fiber post or cast post and core) and the presence and thickness of a ferrule (without ferrule, presence of 0.5-mm or 1-mm-thick ferrule, retaining unaltered 2-mm ferrule height). The root posts and the metal crowns were cemented using an adhesive cement. The samples were subjected to mechanical cycling (at 37°C, 45°, 130 N, 2.2 Hz, and 2 × 106 pulses). Afterward, they were subjected to a fracture load test at a speed of 0.5 mm/min and on a 45° slope until failure occurred. The failures were classified as favorable or unfavorable. The fracture resistance data were analyzed with two-way analysis of variance and Tukey test. The chi-square test was used to analyze the pattern of failure. RESULTS: When considering the cast post and core, the 1-mm ferrule thickness group presented a higher resistance to fracture than did the group in which a ferrule was not used (p=0.001). When using a glass fiber post, the groups showed no differences in fracture resistance. Overall, 96.7% of the specimens survived the mechanical cycling. Of the fractures, 58.6% of the fractures were unfavorable, while 41.6% were favorable. CONCLUSIONS: A thicker ferrule statistically increased the fracture resistance only for cast post and core when it was at least 1 mm thick, despite causing more unfavorable failures. Thus, ferrule thickness should be considered when choosing different intracanal posts, to reduce the occurrence of unfavorable failures. In the absence of a ferrule, the use of a cast post and core presents more favorable failures, and in the presence of a 1-mm-thick ferrule, the use of a glass fiber post seems to be the best clinical decision.


Asunto(s)
Técnica de Perno Muñón , Fracturas de los Dientes , Diente no Vital , Animales , Bovinos , Coronas , Análisis del Estrés Dental , Vidrio , Incisivo
5.
Urologe A ; 44(2): 166-8, 2005 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-15614438

RESUMEN

The ruptured abdominal aortic aneurysm is a rare, but life-threatening disease that demands fast diagnosis. We report in the following about a patient who was admitted with symptoms of urinary obstruction and an acute abdomen. Ultrasound investigation at admission confirmed urinary obstruction of the right kidney. Causative for that however was a right pararenal ruptured abdominal aortic aneurysm, which led secondarily to ureter compression. Thus, in our opinion, primary ultrasound examination represents an important instrument in differential diagnosis.


Asunto(s)
Aneurisma de la Aorta/diagnóstico por imagen , Rotura de la Aorta/diagnóstico por imagen , Urgencias Médicas , Ultrasonografía Doppler Dúplex , Aneurisma de la Aorta/cirugía , Rotura de la Aorta/cirugía , Implantación de Prótesis Vascular , Diagnóstico Diferencial , Humanos , Hidronefrosis/diagnóstico por imagen , Cálculos Renales/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Hemorragia Posoperatoria/diagnóstico por imagen , Hemorragia Posoperatoria/cirugía , Reoperación , Sensibilidad y Especificidad , Trombosis/diagnóstico por imagen , Tomografía Computarizada por Rayos X
6.
Magn Reson Imaging ; 19(10): 1275-7, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11804754

RESUMEN

The incidence of acute colonic diverticulitis (ACD) is increasing. To allow rational therapeutic decisions to be made, a timely diagnosis is required. The feasibility of "on-admission-MRI" to establish the diagnosis has not yet been studied. Therefore, a prospective observational study was carried out in 20 patients with an established diagnosis of ACD. The diagnostic criteria for the MRI diagnosis of ACD were the demonstration of at least one diverticulum, pericolic exudation, and edema of the colonic wall. MRI was diagnostic in all but one patient. It is concluded that MRI has considerable diagnostic potential in ACD and should be formally evaluated.


Asunto(s)
Diverticulitis del Colon/patología , Imagen por Resonancia Magnética , Enfermedad Aguda , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
7.
Chirurg ; 73(5): 443-50, 2002 May.
Artículo en Alemán | MEDLINE | ID: mdl-12089828

RESUMEN

INTRODUCTION: Subjective experiences of patients during their stay in the intensive care unit (ICU) have so far rarely been described. The aim of this study was to analyze the experiences of patients during their stay in the ICU. METHODS: In a prospective study, 100 general surgical ICU patients were recorded consecutively. A questionnaire that covered a broad range of possible ICU experiences was handed out to patients shortly following their stay in ICU. At the same time, a questionnaire was given to the personnel of the ICU to investigate how well nurses and doctors were able to adopt the patients' perspectives of the ICU experience. RESULTS: Concerning the physical symptoms, insomnia was to the fore (67% of patients). Despite pain medication, 25% of patients reported severe pain. The main psychological symptom was a feeling of helplessness (29% of patients). As a general cause for concern, 48% of patients complained about limited mobility. The patients were critical of the presence of severely ill patients. The standards of nursing and medical attention, however, were judged very positively. The evaluation of the staff differed from the patients' experiences in many respects; the clearest differences concerned the items of pain, sleeping disorders and the observance of privacy. CONCLUSIONS: The study results led to several practical consequences in the quality of management procedure (e.g., the introduction of a thorough night's rest at the ICU, optimized information for patients). Additionally, we initiated further studies concerning the quality of life of ICU patients.


Asunto(s)
Unidades de Cuidados Intensivos , Satisfacción del Paciente , Complicaciones Posoperatorias/psicología , Rol del Enfermo , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Grupo de Atención al Paciente , Calidad de Vida/psicología , Índice de Severidad de la Enfermedad , Trastornos del Inicio y del Mantenimiento del Sueño/psicología
8.
Dtsch Med Wochenschr ; 136(42): 2140-4, 2011 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-21990057

RESUMEN

BACKGROUND AND OBJECTIVE: Quality of life is of vital importance for patients undergoing surgery. However, little is known about the quality of life of surgeons who are facing a stressful and dramatically changing working environment. For this reason, this large scale study investigated the quality of life (QL) of surgeons in Germany in the context of occupational, private, and system-related risk factors with a standardized QL measurement instrument. METHODS: The study population consisted of attendees (surgeons, non-surgical physicians, medical students) of the nine major annual conferences of the German Society of Surgery between 2008 and 2009. Participants filled in a single questionnaire including study-specific questions (demographic variables, professional position, and occupational situation) and a standardized quality of life instrument. Surgeons' responses with regard to their professional situation and their quality of life were contrasted with those of the two controls (non-surgical physicians, i. e. orthopedics, pediatrics, gastroenterologists and medical students). Furthermore, QL scores were compared with German population reference data and with reference data of several patient groups. RESULTS: 3652 individuals (2991 surgeons, 561 non-surgical physicians, 100 medical students) participated in this study. 68 % of the surgeons but only 39 % of the non-surgeons worked more than 60 hours per week on average. Surgeons reported restrictions on their private and family life due to work overload, more so than non-surgeons (74 % vs. 59 %). Responses to the PLC quality of life questionnaire confirmed these results, showing score values lower than those of the German population reference data and of several patient groups. CONCLUSION: The time has come for surgeons to consider their own quality of life, as this is a main issue in their scientific and clinical work with patients.


Asunto(s)
Cirugía General , Médicos/psicología , Calidad de Vida , Sociedades Médicas , Adulto , Alemania , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Proyectos Piloto , Estudiantes de Medicina/psicología , Encuestas y Cuestionarios , Carga de Trabajo/psicología , Carga de Trabajo/estadística & datos numéricos
9.
Thorac Cardiovasc Surg ; 57(1): 22-4, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19169992

RESUMEN

BACKGROUND: The aim of this study was to explore patients' needs and changes to these needs during a hospital stay for coronary artery bypass graft (CABG) surgery. METHODS: 70 patients (60 males; mean age = 64.1; SD = 8.9) reported their needs two days before and ten days after CABG surgery using a specifically developed 15-item questionnaire. Student's T-test was used to detect significant differences. RESULTS: Before CABG, patients rated the need for "preparation for surgery", and after CABG the need for "information about the correct handling of drugs", as the most important. The rating of "information about the correct handling of drugs" showed a significant increase after CABG surgery ( T(69) = - 3.46; P < 0.001) and the need for a "letter with the latest scientific information on heart disease" was significantly reduced during this period ( T(69) = 2.07; P = 0.04). CONCLUSIONS: The results indicate that preparation for surgery should be conducted very carefully without time pressure. Patients should receive more detailed information on prescribed drugs.


Asunto(s)
Puente de Arteria Coronaria , Unidades de Cuidados Coronarios , Hospitalización , Pacientes Internos , Evaluación de Necesidades , Evaluación de Procesos y Resultados en Atención de Salud , Anciano , Fármacos Cardiovasculares/uso terapéutico , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Persona de Mediana Edad , Educación del Paciente como Asunto , Cuidados Posoperatorios , Cuidados Preoperatorios , Encuestas y Cuestionarios , Factores de Tiempo , Resultado del Tratamiento
10.
Zentralbl Chir ; 130(5): 440-8, 2005 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-16220441

RESUMEN

Aim of our study has been the systematic evaluation concerning the still farmost unknown disease of postoperative, permanent hypoparathyroidism. For this we designed a specific questionnaire as measuring instrument--it was evaluated by experts and validated by 3 control groups--to examine then a patient group (n = 20) with symptomatic postoperative, permanent hypoparathyroidism. The application of the questionnaire was very feasible, the reliability of measuring scales according to Cronbach's alpha > or = 0.70. The validity of content and construct validity fully existed (Pearson's correlation coefficient r > or = - 0.27; p < 0,05). The farmost frequent clinical complaints were peripheral cold sensations (65 %), pains in joints (55 %), sensation of heaviness and weakness in extremities (55 %) and paresthesias (45 %). Most frequent clinical symptoms were brittle nails (40 %) and diarrhoea (35 %). Sum and distress level scores for classification of illness severity were determined. In conclusion our questionnaire is a valid instrument and from a clinical point of view easy to apply, reasonable and very feasible in practical use. It represents a novel, optimum instrument to determine disease condition and illness severity of hypoparathyroid patients and makes it possible to gain further information of this up to now less systematically analysed disease.


Asunto(s)
Hipoparatiroidismo/psicología , Paratiroidectomía , Satisfacción del Paciente , Complicaciones Posoperatorias/psicología , Rol del Enfermo , Perfil de Impacto de Enfermedad , Tiroidectomía , Adulto , Anciano , Estudios de Factibilidad , Femenino , Humanos , Hipoparatiroidismo/diagnóstico , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Psicometría/estadística & datos numéricos , Reproducibilidad de los Resultados , Encuestas y Cuestionarios
11.
Dtsch Med Wochenschr ; 130(44): 2501-6, 2005 Nov 04.
Artículo en Alemán | MEDLINE | ID: mdl-16252209

RESUMEN

BACKGROUND AND OBJECTIVE: Postoperative hypoparathyroidism is a rare, but complex endocrine disorder. The purpose of this case series study was to evaluate the symptoms, signs and sequelae of the disease in a major homogeneous patient group after the Chernobyl accident in the Ukraine. PATIENTS AND METHODS: This study is based on a random sample of 25 patients with symptomatic permanent hypoparathyroidism after surgical procedures on the thyroid for carcinoma following the Chernobyl accident in May 1986. They underwent physical examination and their parathyroid hormone and calcium levels in serum were determined. The signs, symptoms and sequelae of their disease were systematically assessed by a validated specific questionnaire. The extent of individual distress by the symptoms and signs were analysed by using a Likert scale (points between 1 = no and 5 = maximal distress). RESULTS: In 14 patients (56%) (age at time of operation: 18.24 +/- 4.26 years) paresthesias occurred at least every third day. Very frequent general symptoms were joint pains and hair loss (in 17 patients / 68%). 19 patients (76%) had enamel defects, 17 (68%) increasingly dry skin since the operation. Psychical symptoms like excitability (20 patients / 80%) and depressed mood since the operation (16 patients / 64%) were strikingly frequent. The patients were affected more by dry skin (2,76 on the Likert scale) than by paraesthesias (2,56) or joint pains (2,68) and most of all by depressive mood (2.96) and excitability (3.38). 4 patients (16%) had kidney stones, while osteoporosis and osteosclerosis occurred in 7 (28%) respectively 3 persons (12%). 6 patients (24%) had cataracts and 3 (12%) had basal ganglia calcification. Interestingly, 1/3 of all patients had only non-characteristic symptoms of the disease consistent with a latent form of hypoparathyroidism. CONCLUSIONS: Our data partly show a severe form of hypoparathyroidism of very young persons in the Chernobyl region, a finding which strongly supports the need of exact diagnosis and interdisciplinary treatment options of this postoperative disorder.


Asunto(s)
Accidente Nuclear de Chernóbil , Hipoparatiroidismo/etiología , Neoplasias Inducidas por Radiación/cirugía , Complicaciones Posoperatorias/etiología , Neoplasias de la Tiroides/cirugía , Adolescente , Adulto , Artralgia/etiología , Niño , Esmalte Dental/patología , Depresión/etiología , Femenino , Humanos , Hipoparatiroidismo/complicaciones , Hipoparatiroidismo/psicología , Escisión del Ganglio Linfático/efectos adversos , Masculino , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/etiología , Parestesia/etiología , Complicaciones Posoperatorias/psicología , Factores de Riesgo , Encuestas y Cuestionarios , Neoplasias de la Tiroides/etiología , Tiroidectomía/efectos adversos , Ucrania
12.
World J Surg ; 25(5): 578-84, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11369983

RESUMEN

Diagnosing acute appendicitis (aA) remains difficult. This study evaluated the utility of ultrasonography (US) compared to clinical decision-making alone and scoring systems to establish the indication for laparotomy in patients in whom aA was suspected. The prospectively documented data of 2209 patients admitted for suspicion of aA, who underwent US by one of 12 surgeons, formed a database in which the diagnostic and procedural performance of clinical decision-making, US, two scoring systems (Ohmann and Eskelinen scores), and clinical algorithms taking account of clinical and either US findings or score results, were retrospectively evaluated. The results of either modality were correlated with final diagnoses obtained by laparotomy in 696 patients, of whom 540 had aA (prevalence 24.45%) and follow-up data in the remainder. US had the highest specificity (97%, compared to 93% for the Ohmann and Eskelinen scores and 94% for the clinical evaluation and algorithms) and lowest overall rate of false-positive findings (negative laparotomy rate 7.6%). The scores were accurate in refuting the diagnosis of aA but otherwise not superior to US. The best overall diagnostic and procedural results were obtained with the algorithms that combined the results of either US or the Ohmann score with clinical evaluation, which produced the most favorable numbers of negative laparotomies, potential perforations, and missed cases of aA. US is the diagnostic standard of reference for patients with a possible diagnosis of aA. It yields diagnostic results superior to those of scoring systems and provisional clinical evaluation. However, the benefits of US by ultrasonographically trained surgeons are only fully appreciated within the context of clinical algorithms. The joint evaluation of score results and clinical evaluation may deliver information of similar accuracy.


Asunto(s)
Apendicitis/diagnóstico por imagen , Apendicitis/diagnóstico , Toma de Decisiones , Enfermedad Aguda , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Ultrasonografía
13.
Dig Dis Sci ; 41(1): 216-25, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8565759

RESUMEN

Physiologic bile reflux was assessed in 27 in vivo test with healthy volunteers to define a standardized protocol and normal values for 24-hour enterogastric bile reflux monitoring (protocol with supine, upright, and meal phases and a free diet avoiding alcohol, smoking, and coffee, evaluation with different thresholds of absorbance units: 0.14, 0.25). In vitro tests with bile-sodium solutions demonstrated a linear dependence of absorbance for bilirubin up to 600 mumol/liter (range of the fiberoptic device: 0.0-1.0). Fluids and food might interfere with absorbances below 0.25 (exception: coffee). In vivo bile often remains in the stomach for more than 1 hr; these events were defined as reflux episodes. The upper limits for physiologic bile reflux are a percentage of total time of bile reflux of 28.2% and an average absorbance during a reflux episode of 0.62 (95th percentile with threshold 0.25). Comparing bile with pH monitoring (absorbance > 0.25 and/or pH > 4), an increase of bilirubin was found most frequently with constant pH (45%) or an increase of pH with constant bilirubin (36%). The hypothesis was drawn that bile and duodenal or pancreatic secretions may separately contribute to duodenogastric reflux.


Asunto(s)
Reflujo Biliar/fisiopatología , Bilis/fisiología , Monitoreo Ambulatorio/instrumentación , Estómago/fisiología , Adulto , Bilirrubina/análisis , Ingestión de Líquidos , Ingestión de Alimentos , Femenino , Tecnología de Fibra Óptica , Determinación de la Acidez Gástrica , Humanos , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Valores de Referencia , Reproducibilidad de los Resultados , Estómago/fisiopatología
14.
Glycobiology ; 11(11): 997-1008, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11744634

RESUMEN

The presence of alpha2,8-linked polysialic acid on the neural cell adhesion molecule (NCAM) is known to modulate cell interactions during development and oncogenesis. Two enzymes, the alpha2,8-polysialyltransferases ST8Sia IV()/PST and ST8Sia II()/STX are responsible for the polysialylation of NCAM. We previously reported that both ST8Sia IV/PST and ST8Sia II/STX enzymes are themselves modified by alpha2,8-linked polysialic acid chains, a process called autopolysialylation. In the case of ST8Sia IV/PST, autopolysialylation is not required for enzymatic activity. However, whether the autopolysialylation of ST8Sia II/STX is required for its ability to polysialylate NCAM is unknown. To understand how autopolysialylation impacts ST8Sia II/STX enzymatic activity, we employed a mutagenesis approach. We found that ST8Sia II/STX is modified by six Asn-linked oligosaccharides and that polysialic acid is distributed among the oligosaccharides modifying Asn 89, 219, and 234. Coexpression of a nonautopolysialylated ST8Sia II/STX mutant with NCAM demonstrated that autopolysialylation is not required for ST8Sia II/STX polysialyltransferase activity. In addition, catalytically active, nonautopolysialylated ST8Sia II/STX does not polysialylate any endogenous COS-1 cell proteins, highlighting the protein specificity of polysialylation. Furthermore, immunoblot analysis of NCAM polysialylation by autopolysialylated and nonautopolysialylated ST8Sia II/STX suggests that the NCAM is polysialylated to a higher degree by autopolysialylated ST8Sia II/STX. Therefore, we conclude that autopolysialylation of ST8Sia II/STX, like that of ST8Sia IV/PST, is not required for, but does enhance, NCAM polysialylation.


Asunto(s)
Molécula L1 de Adhesión de Célula Nerviosa , Moléculas de Adhesión de Célula Nerviosa/metabolismo , Ácidos Siálicos/metabolismo , Sialiltransferasas/metabolismo , Animales , Asparagina/química , Secuencia de Bases , Sitios de Unión , Células COS , ADN Complementario/genética , Glicosilación , Mutagénesis Sitio-Dirigida , Oligosacáridos/química , Procesamiento Proteico-Postraduccional , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sialiltransferasas/química , Sialiltransferasas/genética
15.
MAGMA ; 12(1): 4-9, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11255086

RESUMEN

PURPOSE: The purpose of this study was to evaluate MRI as a diagnostic tool in patients with suspected acute sigmoid diverticulitis. Furthermore, we sought to develop an optimal imaging protocol in these patients. PATIENTS AND METHODS: Eleven patients with suspected acute diverticulitis were included in the study. All patients were imaged in a 1.0 T clinical scanner using a body-array coil. Imaging sequences were single-shot TSE, HASTE-, STIR- and TrueFisp- sequence. All were obtained in the frontal plane. The diagnosis was verified by a single experienced investigator, using ultrasound, and overall clinicopathological outcome. RESULTS: MRI enabled visualization of signs of an acute diverticulitis in all patients. However, the diagnosis of acute diverticulitis was obtained in 10 patients only. The mean imaging time was 17.5+/-5.5 min. STIR- and TrueFisp-sequences alone displayed all findings, e.g pericolonic exsudation, edema and segmental narrowing, whereas SSTSE and HASTE-sequences showed no additional information. Therefore, it appeared that the imaging protocol could be restricted to STIR- and TrueFisp-sequences. CONCLUSION: MRI is feasible as a fast, accurate and investigator-independent diagnostic tool in patients with suspected acute diverticulitis. To prove its value in comparison to computed tomography or ultrasound, further studies are needed.


Asunto(s)
Colon Sigmoide , Diverticulitis del Colon/diagnóstico , Imagen por Resonancia Magnética , Enfermedad Aguda , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
16.
World J Surg ; 24(11): 1361-6, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11038207

RESUMEN

Permanent hypoparathyroidism is one of the most difficult of all endocrine disorders to treat medically. Because this deficiency syndrome rarely is a life-threatening condition, systemic immunosuppression for recipients of transgenic transplants is not justified. An alternative would be protecting the tissue to be transplanted from the immunologic response (immunoisolation) by coating it with a semipermeable membrane- microencapsulation. Unfortunately, prior to the first clinical use, further analysis of the coating substance (alginate) demonstrated that it has potential cancerogenic properties. Using a purified amitogenic alginate suitable for clinical use, we accomplished allotransplantation in a long-term animal model and reported the first clinical cases without postoperative immunosuppression recently. In view of the potential clinical use, we investigated the ability of the microencapsulation technology with the novel amitogenic alginate in experimental hypoparathyroidism (80 parathyroidectomized rats) to enable transgenic transplantation across the highest immunologic barrier (xenotransplantation: human to rat) to ensure intact transplant function without immunosuppression. In a controlled, long-term animal study, the effect of microencapsulation on xenotransplanted human parathyroid tissue was evaluated over a period of 30 weeks (microencapsulated and naked hyperplastic parathyroid tissue, respectively). Functionally, human parathyroid tissue was able to replace that of rats. More than 6 months after xenotransplantation 32 of 40 animals that had received microencapsulated transplants were normocalcemic. In contrast, serum calcium concentrations dropped to postparathyroidectomy levels within 3 weeks in the animals that had received naked tissue only. Correspondingly, normocalcemic animals showed vital parathyroid tissue inside the microcapsules, which were surrounded by a small rim of fibroblasts. When combining microencapsulation with an improved tissue culture method, xenotransplantation of human parathyroid tissue and maintenance of its physiologic function is reproducibly achieved over the highest transplantation barrier. Using the amitogenic alginate may be a crucial step toward the first clinical use of this technique for parathyroid xenotransplantation without immunosuppression.


Asunto(s)
Alginatos , Composición de Medicamentos , Hipoparatiroidismo/cirugía , Glándulas Paratiroides/trasplante , Trasplante Heterólogo/métodos , Animales , Materiales Biocompatibles , Modelos Animales de Enfermedad , Estudios de Seguimiento , Ácido Glucurónico , Ácidos Hexurónicos , Terapia de Inmunosupresión , Masculino , Glándulas Paratiroides/fisiología , Complicaciones Posoperatorias/prevención & control , Ratas , Ratas Endogámicas Lew , Ratas Endogámicas , Valores de Referencia , Sensibilidad y Especificidad , Resultado del Tratamiento
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