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1.
Acta Psychiatr Scand ; 147(6): 570-580, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37020420

RESUMEN

INTRODUCTION: Major depressive disorder (MDD) is a common psychiatric disorder. Despite several treatment options, a subgroup of patients will not respond to the commonly used antidepressant treatments and thus express treatment resistance (TRD). TRD can be quantified with the Dutch Measure for Treatment Resistance in Depression (DM-TRD). Electroconvulsive therapy (ECT) is an effective treatment for MDD, also in TRD. Yet, the position of ECT as "treatment-of-last-resort" may decrease the likelihood of beneficial outcome. Our aim was to investigate the association between treatment resistance and outcome and course of ECT. METHODS: We performed a retrospective, multicenter cohort study with 440 patients of which data was retrieved from patient records as collected in the Dutch ECT Cohort database. Linear and logistic regression models were used to explore the association between level of treatment resistance and outcome of ECT. Median split was used to explore the differences between high and low level of TRD and course of treatment. RESULTS: A higher DM-TRD score was associated with significantly smaller reduction of depression symptoms (R2 = 0.160; ß = -2.968; p < 0.001) and lower chance of response (OR = 0.821 [95 CI: 0.760-0.888]; ß = -0.197; p < 0.001). Low level TRD patients underwent fewer ECT sessions (mean 13 ± 6 SD vs. 16 ± 7 SD; p < 0.001) and fewer switches from right unilateral tot bifrontotemporal electrode placement (29% vs. 40%; p = 0.032). CONCLUSION: Reserving ECT as "treatment-of-last-resort" in the treatment algorithm for MDD seems questionable, because in our study lower level of treatment resistance predicted more beneficial ECT-outcome. Moreover, providing ECT in less treatment resistant patients showed fewer needed ECT-sessions and less switches to BL electrode placement, which may decrease the risk for cognitive side-effects.


Asunto(s)
Trastorno Depresivo Mayor , Trastorno Depresivo Resistente al Tratamiento , Terapia Electroconvulsiva , Humanos , Terapia Electroconvulsiva/efectos adversos , Trastorno Depresivo Mayor/terapia , Estudios Retrospectivos , Estudios de Cohortes , Trastorno Depresivo Resistente al Tratamiento/terapia , Trastorno Depresivo Resistente al Tratamiento/diagnóstico , Resultado del Tratamiento
2.
Front Oncol ; 12: 1003506, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36330470

RESUMEN

Background: The probability of undergoing treatment with curative intent for esophagogastric cancer has been shown to vary considerately between hospitals of diagnosis. Little is known about the factors that attribute to this variation. Since clinical decision making (CDM) partially takes place during an MDTM, the aim of this qualitative study was to assess clinician's perspectives regarding facilitators and barriers associated with CDM during MDTM, and second, to identify factors associated with CDM during an MDTM that may potentially explain differences in hospital practice. Methods: A multiple case study design was conducted. The thematic content analysis of this qualitative study, focused on 16 MDTM observations, 30 semi-structured interviews with clinicians and seven focus groups with clinicians to complement the collected data. Interviews were transcribed ad verbatim and coded. Results: Factors regarding team dynamics that were raised as aspects attributing to CDM were clinician's personal characteristics such as ambition and the intention to be innovative. Clinician's convictions regarding a certain treatment and its outcomes and previous experiences with treatment outcomes, and team dynamics within the MDTM influenced CDM. In addition, a continuum was illustrated. At one end of the continuum, teams tended to be more conservative, following the guidelines more strictly, versus the opposite in which hospitals tended towards a more invasive approach maximizing the probability of curation. Conclusion: This study contributes to the awareness that variation in team dynamics influences CDM during an MDTM.

3.
BMC Health Serv Res ; 22(1): 527, 2022 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-35449018

RESUMEN

BACKGROUND: Among esophagogastric cancer patients, the probability of having undergone treatment with curative intent has been shown to vary, depending on the hospital of diagnosis. However, little is known about the factors that contribute to this variation. In this study, we sought to understand the organization of clinical pathways and their association with variation in practice. METHODS: A mixed-method study using quantitative and qualitative data was conducted. Quantitative data were obtained from the Netherlands Cancer Registry (e.g., outpatient clinic consultations and diagnostic procedures). For qualitative data, thematic content analysis was performed using semi-structured interviews (n = 30), observations of outpatient clinic consultations (n = 26), and multidisciplinary team meetings (MDTM, n = 16) in eight hospitals, to assess clinicians' perspectives regarding the clinical pathways. RESULTS: Quantitative analyses showed that patients more often underwent surgical consultation prior to the MDTM in hospitals associated with a high probability of receiving treatment with curative intent, but more often consulted with a geriatrician in hospitals associated with a low probability of such treatment. The organization of clinical pathways was analyzed quantitatively at three levels: regional, local, and patient levels. At a regional level, hospitals differed in terms of the number of patients discussed during the MDTM. At the local level, the revision of radiological images and restaging after neoadjuvant treatment varied. At the patient level, some hospitals routinely conduct fitness tests, whereas others estimated the patient's physical fitness during an outpatient clinic consultation. Few clinicians performed a standard geriatric consultation in older patients to assess their mental fitness and frailty. CONCLUSION: Surgical consultation prior to MDTM was more often conducted in hospitals associated with a high probability of receiving treatment with curative intent, whereas a geriatrician was consulted more often in hospitals associated with a low probability of receiving such treatment.


Asunto(s)
Neoplasias Esofágicas , Neoplasias Gástricas , Anciano , Vías Clínicas , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/terapia , Hospitales , Humanos , Probabilidad , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/terapia
4.
Eur J Surg Oncol ; 48(2): 348-355, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34366174

RESUMEN

BACKGROUND: This study aims to assess the impact of nationwide centralization of surgery on travel distance and travel burden among patients with oesophageal, gastric, and pancreatic cancer according to age in the Netherlands. As centralization of care increases to improve postoperative outcomes, travel distance and experienced burden might increase. MATERIALS AND METHODS: All patients who underwent surgery between 2006 and 2017 for oesophageal, gastric and pancreatic cancer in the Netherlands were included. Travel distance between patient's home address and hospital of surgery in kilometres was calculated. Questionnaires were used to assess experienced travel burden in a subpopulation (n = 239). Multivariable ordinal logistic regression models were constructed to identify predictors for longer travel distance. RESULTS: Over 23,838 patients were included, in whom median travel distance for surgical care increased for oesophageal cancer (n = 9217) from 18 to 28 km, for gastric cancer (n = 6743) from 9 to 26 km, and for pancreatic cancer (n = 7878) from 18 to 25 km (all p < 0.0001). Multivariable analyses showed an increase in travel distance for all cancer types over time. In general, patients experienced a physical and social burden, and higher financial costs, due to traveling extra kilometres. Patients aged >70 years travelled less often independently (56% versus 68%), as compared to patients aged ≤70 years. CONCLUSION: With nationwide centralization, travel distance increased for patients undergoing oesophageal, gastric, and pancreatic cancer surgery. Younger patients travelled longer distances and experienced a lower travel burden, as compared to elderly patients. Nevertheless, on a global scale, travel distances in the Netherlands remain limited.


Asunto(s)
Costo de Enfermedad , Procedimientos Quirúrgicos del Sistema Digestivo , Neoplasias Esofágicas/cirugía , Accesibilidad a los Servicios de Salud , Neoplasias Pancreáticas/cirugía , Neoplasias Gástricas/cirugía , Oncología Quirúrgica/organización & administración , Viaje , Factores de Edad , Anciano , Femenino , Gastos en Salud , Planificación Hospitalaria , Hospitales , Hospitales de Alto Volumen , Hospitales de Bajo Volumen , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Países Bajos , Derivación y Consulta , Encuestas y Cuestionarios
5.
Br J Surg ; 108(7): 826-833, 2021 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-33738473

RESUMEN

BACKGROUND: Centralization of pancreatic surgery in the Netherlands has been ongoing since 2011. The aim of this study was to assess how centralization has affected the likelihood of resection and survival of patients with non-metastatic pancreatic head and periampullary cancer, diagnosed in hospitals with and without pancreatic surgery services. METHODS: An observational cohort study was performed on nationwide data from the Netherlands Cancer Registry (2009-2017), including patients diagnosed with non-metastatic pancreatic head or periampullary cancer. The period of diagnosis was divided into three time intervals: 2009-2011, 2012-2014 and 2015-2017. Hospital of diagnosis was classified as a pancreatic or non-pancreatic surgery centre. Analyses were performed using multivariable logistic and Cox regression models. RESULTS: In total, 10 079 patients were included, of whom 3114 (30.9 per cent) were diagnosed in pancreatic surgery centres. Between 2009-2011 and 2015-2017, the number of patients undergoing resection increased from 1267 of 3169 (40.0 per cent) to 1705 of 3566 (47.8 per cent) (P for trend < 0.001). In multivariable analysis, in 2015-2017, unlike the previous periods, patients diagnosed in pancreatic and non-pancreatic surgery centres had a similar likelihood of resection (odds ratio 1.08, 95 per cent c.i. 0.90 to 1.28; P = 0.422). In this period, however, overall survival was higher in patients diagnosed in pancreatic surgery than in those diagnosed in non-pancreatic surgery centres (hazard ratio 0.92, 95 per cent c.i. 0.85 to 0.99; P = 0.047). CONCLUSION: After centralization of pancreatic surgery, the resection rate for patients with pancreatic head and periampullary cancer diagnosed in non-pancreatic surgery centres increased and became similar to that in pancreatic surgery centres. Overall survival remained higher in patients diagnosed in pancreatic surgery centres.


Asunto(s)
Cirugía General/organización & administración , Pancreatectomía/estadística & datos numéricos , Neoplasias Pancreáticas/mortalidad , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Países Bajos/epidemiología , Pancreatectomía/mortalidad , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/cirugía , Estudios Prospectivos , Tasa de Supervivencia/tendencias
6.
Eur J Surg Oncol ; 45(10): 1882-1886, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31202571

RESUMEN

INTRODUCTION: Hospital of diagnosis is shown to have an impact on the probability of undergoing a resection in different types of gastrointestinal cancer. The aim of this study was to investigate the inter-hospital variation in resection rates and its impact on survival among patients with non-metastatic colon cancer. METHODS: All patients diagnosed with non-metastatic colon cancer between 2009 and 2014 were selected from the Netherlands Cancer Registry. Multilevel logistic regression was used to examine the variation in resection rates among hospitals. The effect of variation in surgical resection on overall survival was assessed using Cox regression analyses. Relative survival was used as an estimate for disease-specific survival. RESULTS: 38164 patients, treated in 95 different hospitals, were included in the analysis. After adjustments, resection rates varied between hospitals from 88 to 99%. This variation increased among patients older than 75 years, from 79 to 98%. Crude overall 5-year survival was 64%. After adjustment, no significant difference in overall or relative survival between hospitals with higher and lower resection rates was observed. CONCLUSION: Resection rates are important to consider when interpreting hospital outcomes. There is a significant variation in resection rates in patients with non-metastatic colon cancer among hospitals in the Netherlands. This variation increases in the elderly. No significant effect on survival was found. This could imply that undertreatment may play a role as well as that some patients might not benefit from surgery.


Asunto(s)
Colectomía/estadística & datos numéricos , Neoplasias del Colon/cirugía , Hospitales de Alto Volumen/estadística & datos numéricos , Hospitales de Bajo Volumen/estadística & datos numéricos , Vigilancia de la Población/métodos , Sistema de Registros , Anciano , Neoplasias del Colon/epidemiología , Femenino , Estudios de Seguimiento , Mortalidad Hospitalaria/tendencias , Humanos , Incidencia , Masculino , Países Bajos/epidemiología , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia/tendencias
7.
Eur J Cancer ; 79: 61-71, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28463757

RESUMEN

BACKGROUND: Type 2 diabetes mellitus (T2DM) may be a risk factor for gastrointestinal (GI) cancers, but variations in study designs of observational studies may have yielded biased results due to detection bias. Furthermore, differences in risk for GI cancer subsites have not been extensively evaluated. We aimed to determine the risk of GI cancer and its subsites in patients with T2DM and how it is affected by detection bias. METHODS: A matched cohort study was performed using the NCR-PHARMO database. New-users of ≥1 non-insulin anti-diabetic drug during 1998-2011 were matched with non-diabetic controls by year of birth, sex, and time between database entry and index. Cox regression analyses were performed with and without lag-period to estimate hazard ratios (HRs) for GI cancer and its subsites. Covariables included age, sex, use of other drugs and history of hospitalisation. RESULTS: An increased risk of GI cancer was observed in T2DM patients (HR 1.5, 95% confidence interval [CI] 1.3-1.7) compared with controls, which was attenuated in the 1-year lagged analysis (HR 1.4, 95% CI 1.2-1.7). Stratified by subsite, statistically significant increased risks of pancreatic (HR 4.7, 95% CI 3.1-7.2), extrahepatic bile duct (HR 4.2, 95% CI 1.5-11.8) and distal colon cancer (HR 1.5, 95% CI 1.1-2.1) were found, which remained statistically significantly increased in the lagged analysis. CONCLUSIONS: T2DM patients had a 40% increased risk of GI cancer. Increased GI cancer risks tended to be weaker when reducing detection bias by applying a 1-year lag-period. Future observational studies should therefore include sensitivity analyses in which this bias is minimised.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Neoplasias Gastrointestinales/etiología , Distribución por Edad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sistema de Registros , Factores de Riesgo , Distribución por Sexo
9.
Br J Cancer ; 113(3): 403-10, 2015 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-26180924

RESUMEN

BACKGROUND: Metformin, statin and aspirin use seem associated with decreased mortality in cancer patients, though, without adjusting for one another. Independent associations of these drugs with overall mortality after colorectal cancer (CRC) diagnosis within glucose-lowering drugs (GLDs) users were assessed. METHODS: Patients starting GLDs before CRC diagnosis (1998-2011) were selected from the Eindhoven Cancer Registry linked with the PHARMO Database Network. The Cox regression model, with time since CRC diagnosis, included time-dependent variables of cumulative exposure to metformin, statins and aspirin after cancer diagnosis and time-dependent ever-never terms for drug exposure. RESULTS: A total of 1043 patients used GLDs before CRC diagnosis; 666 (64%) used metformin, 639 (61%) used statins and 490 (47%) used aspirin after CRC diagnosis. Multivariable analyses revealed that longer cumulative exposure to metformin was not associated with overall mortality (HRCumulative exposure/6 months 1.02; 95% CI 0.97-1.07), whereas the favourable effect of statins increased with cumulative exposure (HRCumulative exposure/6 months 0.93; 95% CI 0.89-0.98). No association between aspirin use and overall mortality was seen (HRCumulative exposure/6 months 0.98; 95% CI 0.93-1.03). CONCLUSIONS: No independent association between cumulative exposure to metformin, aspirin and overall mortality was found. Cumulative exposure to statins after CRC diagnosis was associated with lower overall mortality, supporting a drug effect of statins among GLDs users.


Asunto(s)
Aspirina/uso terapéutico , Neoplasias Colorrectales/mortalidad , Diabetes Mellitus/tratamiento farmacológico , Diabetes Mellitus/epidemiología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Metformina/uso terapéutico , Anciano , Anciano de 80 o más Años , Neoplasias Colorrectales/complicaciones , Neoplasias Colorrectales/tratamiento farmacológico , Complicaciones de la Diabetes/epidemiología , Complicaciones de la Diabetes/mortalidad , Diabetes Mellitus/mortalidad , Femenino , Humanos , Hipoglucemiantes/uso terapéutico , Masculino , Persona de Mediana Edad , Sistema de Registros , Factores de Riesgo , Análisis de Supervivencia
10.
Diabetes Metab ; 40(2): 120-7, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24507584

RESUMEN

Colorectal cancer (CRC) patients with pre-existing diabetes have significantly lower rates of overall survival compared with patients without diabetes. Against this backdrop, the American Diabetes Association and American Cancer Society in 2010 reviewed the scientific literature concerning diabetes and cancer. One of the key issues identified for further investigation was the need for a better understanding of whether diabetes influences cancer prognosis above and beyond the prognosis conferred by each disease state independently. Whether the worsened survival of CRC patients with diabetes could be explained by less favourable patient-, tumour- and treatment-related characteristics has also been evaluated in numerous recent studies. However, as most studies did not account for all the various potential confounders, such as cancer stage, comorbidities and body mass index (BMI) in their analyses, the current evidence for the association between diabetes and survival in CRC patients remains inconclusive. Nevertheless, based on multiple examples in the literature, the present review demonstrates that diabetes affects the presentation of CRC as well as its treatment and outcome, which may then result in lower overall rates of survival in patients with, compared to those without, diabetes.


Asunto(s)
Adyuvantes Inmunológicos/uso terapéutico , Neoplasias Colorrectales/mortalidad , Diabetes Mellitus Tipo 2/complicaciones , Hipoglucemiantes/uso terapéutico , Distribución por Edad , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/patología , Comorbilidad , Diabetes Mellitus Tipo 2/mortalidad , Femenino , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Factores de Riesgo , Análisis de Supervivencia , Estados Unidos/epidemiología
11.
J Cancer Surviv ; 7(4): 602-13, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23918453

RESUMEN

PURPOSE: The aim of this study was to assess the difference in explained variance of Health-Related Quality of Life (HRQoL) between comorbidity, sociodemographic characteristics and cancer characteristics. This association was assessed among thyroid cancer, colorectal cancer, and (non-)Hodgkin's lymphoma patients. METHODS: Data from three large population-based surveys on survivors of thyroid cancer, colorectal cancer, and (non-)Hodgkin's lymphoma were used. Cancer-specific HRQoL was assessed with the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) of which physical function, emotional function, fatigue, and pain were included in the analyses. Comorbidity was assessed using the Self-reported Comorbidity Questionnaire. The association between comorbidity and HRQoL was assessed with multivariate linear regression models. Semi-partial R (2) was reported to assess the amount of variance in HRQoL explained by comorbidity in comparison with sociodemographic and cancer characteristics. RESULTS: In total, 3,792 cancer survivors were included in this analysis. The variance in HRQoL subscales explained by comorbidity was higher compared with sociodemographic and cancer characteristics for physical function (11-17 vs. 2-4 and 1-2 %, respectively) and emotional function (7-17 vs. 1-3 and 1-3 %, respectively), regardless of cancer type. In addition, comorbidity explained 7-20 and 11-13 % of the variance in pain and fatigue, respectively, compared to 0-4 % for both sociodemographic and cancer characteristics. Osteoarthritis and back pain were strongly associated with physical function and pain, while depression was strongly associated with emotional function. Depression and back pain were strongly associated with fatigue. CONCLUSIONS: This study showed that comorbidity explained more variance in physical and emotional function, pain, and fatigue in comparison with sociodemographic and cancer characteristics in cancer survivors, regardless of cancer type. Our findings emphasize the importance of adjusting for the presence of comorbid diseases when assessing HRQoL in cancer survivors. IMPLICATION FOR CANCER SURVIVORS: Cancer survivors suffering from comorbid diseases experience lower levels of health-related quality of life. Clinicians should become more aware of the impact of comorbidity on HRQoL and provide necessary psychological support to assist self-management of comorbid diseases.


Asunto(s)
Neoplasias Colorrectales/epidemiología , Estado de Salud , Linfoma no Hodgkin/epidemiología , Calidad de Vida , Sobrevivientes/estadística & datos numéricos , Neoplasias de la Tiroides/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Colorrectales/psicología , Comorbilidad , Femenino , Humanos , Linfoma no Hodgkin/psicología , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Calidad de Vida/psicología , Sistema de Registros/estadística & datos numéricos , Sobrevivientes/psicología , Neoplasias de la Tiroides/psicología
12.
Public Health ; 127(3): 231-40, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23332733

RESUMEN

OBJECTIVES: To examine the association between diet and physical activity and sedentary behaviours in 9-10-year-old children. STUDY DESIGN: A cross-sectional study using data from the SPEEDY (Sport, Physical activity and Eating behaviour: Environmental Determinants in Young People) study undertaken in Norfolk, UK. METHODS: Data from 4-day food diaries and 7 days of accelerometery were matched on concurrent days. Time spent in moderate-to-vigorous physical activity (MVPA), time spent in sedentary behaviour and various measures of dietary intake were collected. Covariates included age, sex, weight status, family socio-economic status, and energy intake reporting quality. Multivariable regression models, adjusted for clustering of children by school and stratified by sex, were fitted to examine the associations between dietary measures and physical activity and sedentary outcomes. RESULTS: In total, 1317 children (584 boys and 733 girls) provided concurrent data. Boys in the highest quartile of energy percentage from protein spent approximately 6 min [95% confidence interval (CI) 0-12] less in MVPA compared with boys in the lowest quartile. Those in the highest quartiles of fruit and vegetable intake and fruit juice intake had respective average activity counts per minute that were 56 above (95% CI 8-105) and 48 below (95% CI 2-95) those in the lowest quartiles, whilst those in the highest quartile of fizzy drink consumption spent approximately 7 min (95% CI 2-13) more in MVPA and approximately 14 min (95% CI 5-24 min) less in sedentary behaviour. Boys in the highest quartile of savoury snack consumption spent approximately 8 min (95% CI 2-13 min) more in MVPA per day, and approximately 12 min (95% CI 2-23) less in sedentary behaviour. No significant associations were apparent among girls. CONCLUSIONS: Few associations were detected, and the directions of those that were apparent were mainly counterintuitive. The extent to which this reflects a true lack of association or is associated with the measurement methods used for diet and physical activity needs further investigation.


Asunto(s)
Dieta/estadística & datos numéricos , Actividad Motora , Conducta Sedentaria , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Reino Unido
13.
Biochem J ; 330 ( Pt 3): 1201-8, 1998 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-9494086

RESUMEN

We present the first characterization of the late photo-intermediates (Meta I, Meta II and Meta III) of a vertebrate cone pigment in a lipid environment. Marked differences from the same pathway in the rod pigment were observed. The histidine-tagged human green cone pigment was functionally expressed in large-scale suspension cultures in Sf9 insect cells using recombinant baculovirus. The recombinant pigment was extensively purified in a single step by immobilized metal affinity chromatography and displays the expected spectral characteristics. The purified pigment was able to activate the rod G-protein transducin at about half the rate of the rod pigment. Following reconstitution into bovine retina lipid proteoliposomes, identification and analysis of the photo-intermediates Meta I, Meta II and Meta III was accomplished. Similar to the rod pigment, our results indicate the existence of a Meta I-Meta II equilibrium, but we find no evidence for pH dependence. Replacement of native Cl- by NO3- in the anion-binding site of the cone pigment affected the spectral position of the pigment itself and of the Meta I intermediate, but not that of Meta II and Meta III. The decay rate of the 'active' intermediate Meta II did not differ for the Cl- and NO3- state. However, in qualitative agreement with results reported before for chicken cone pigments, the rate of Meta II decay was significantly higher in the human cone pigment than in the rod pigment.


Asunto(s)
Proteínas del Ojo/metabolismo , Células Fotorreceptoras Retinianas Conos/fisiología , Animales , Bovinos , Línea Celular , Cromatografía de Afinidad , Proteínas del Ojo/biosíntesis , Proteínas del Ojo/aislamiento & purificación , Humanos , Luz , Liposomas , Fotoquímica , Proteolípidos , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Retina/fisiología , Células Fotorreceptoras Retinianas Conos/química , Células Fotorreceptoras Retinianas Bastones/química , Células Fotorreceptoras Retinianas Bastones/fisiología , Opsinas de Bastones , Lugares Marcados de Secuencia , Espectrofotometría , Spodoptera , Transducina/metabolismo , Transfección
14.
Biochem J ; 330 ( Pt 1): 541-7, 1998 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-9461554

RESUMEN

Microspectrophotometric (msp) studies have shown that the colour-vision system of many bird species is based on four pigments with absorption peaks in the red, green, blue and UV regions of the spectrum. The existence of a fourth pigment (UV) is the major difference between the trichromacy of humans and the tetrachromacy of such birds, and recent studies have shown that it may play a determining role in such diverse aspects of behaviour as mate selection and detection of food. Avian visual pigments are composed of an opsin protein covalently bound via a Schiff-base linkage to the chromophore 11-cis-retinal. Here we report the cDNA sequence of a UV opsin isolated from an avian species, Melopsittacus undulatus (budgerigar or small parakeet). This sequence has been expressed using the recombinant baculovirus system; the pigment generated from the expressed protein on addition of 11-cis-retinal yielded an absorption spectrum typical of a UV photopigment, with lambdamax 365+/-3 nm. This is the first UV opsin from an avian species to be sequenced and expressed in a heterologous system. In situ hybridization of this sequence to budgerigar retinas selectively labelled a sub-set of UV cones, representing approx. 9% of the total cone population, that are distributed in a semi-regular pattern across the entire retina.


Asunto(s)
Periquitos/fisiología , Células Fotorreceptoras Retinianas Conos/fisiología , Opsinas de Bastones/fisiología , Visión Ocular/fisiología , Secuencia de Aminoácidos , Animales , Clonación Molecular , ADN Complementario/genética , Genes , Hibridación in Situ , Proteínas de la Membrana/química , Datos de Secuencia Molecular , Filogenia , Proteínas Recombinantes , Análisis Espectral , Rayos Ultravioleta
15.
FEBS Lett ; 396(1): 26-30, 1996 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-8906860

RESUMEN

Mammalian color vision is mediated by light-sensitive pigments in retinal cone cells. Biochemical studies on native mammalian cone visual pigments are seriously hampered by their low levels and instability. We describe a novel approach for their functional expression, employing the baculovirus system in combination with histidine tagging to allow future purification and structural analysis. The human red and green cone pigments are produced in relatively large amounts and can be detected by immunocytochemistry as well as by immunoblotting. Histidine tagging has no significant effect on the absorbance maxima. The first evidence is presented that these pigments are N-glycosylated.


Asunto(s)
Baculoviridae/genética , Histidina/metabolismo , Células Fotorreceptoras Retinianas Conos/química , Pigmentos Retinianos/genética , Pigmentos Retinianos/metabolismo , Secuencia de Aminoácidos , Animales , Baculoviridae/metabolismo , Secuencia de Bases , Proteínas Portadoras/química , Proteínas Portadoras/metabolismo , Membrana Celular/metabolismo , Células Cultivadas , ADN Complementario/química , ADN Complementario/genética , Glicosilación , Humanos , Inmunohistoquímica , Microscopía Confocal , Datos de Secuencia Molecular , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Pigmentos Retinianos/química , Análisis Espectral/métodos , Spodoptera/citología , Spodoptera/genética , Spodoptera/virología , Rayos Ultravioleta
16.
J Immunol Methods ; 142(2): 187-98, 1991 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-1717598

RESUMEN

Three mouse monoclonal antibodies (Moabs) have been obtained with specificity for the 7B2 protein, a proposed member of the granin family of neuroendocrine proteins. Bacterially produced hybrid proteins of 7B2 were used as immunogens. The Moabs were designated MON-100, MON-101, and MON-102. Furthermore, we report the construction of 35 deletion mutants of the glutathione S-transferase-7B2 (GST-7B2) fusion-gene using recombinant DNA technology. The hybrid proteins encoded by eleven of these mutants were used in epitope mapping experiments and the results of these studies strongly suggested that recognition of 7B2 by all three Moabs involved the same 16 amino acid region of 7B2 (from amino acid residue 128-135). This was further substantiated by the observation that MON-101 and MON-102 specifically recognized a conjugate between bovine serum albumin and the synthetic peptide Phe-Glu-Pro-Glu-His-Asp-Tyr-Pro-Gly-Leu-Gly-Lys based upon the deduced amino acid sequence of the predicted epitope region in 7B2. In an approach to generate a series of 7B2-specific Moabs targeted against another epitope region in the 7B2 protein, the hybrid protein encoded by deletion mutant pPV32 was used as the immunogen. This protein lacked the epitope region recognized by the first series of Moabs. A second series of three Moabs, designated MON-142, MON-143, and MON-144, was obtained and, in all three cases, the region of 7B2 from amino acid residue 64-94 appeared to be involved in specific recognition by the Moabs. The whole panel of six anti-7B2 antibodies appeared to be useful in immunoprecipitation and Western blot analysis of the 7B2 protein and specifically stained neuroendocrine cells in immunohistochemical experiments. Using a double determinant sandwich enzyme immunoassay, 7B2 protein levels in rat pituitary were determined as 20 ng/mg tissue.


Asunto(s)
Biomarcadores de Tumor/inmunología , Clonación Molecular , Epítopos/genética , Proteínas del Tejido Nervioso , Mapeo Peptídico/métodos , Hormonas Hipofisarias/fisiología , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/biosíntesis , Anticuerpos Monoclonales/inmunología , Western Blotting , Ensayo de Inmunoadsorción Enzimática , Glutatión Transferasa , Humanos , Isotipos de Inmunoglobulinas/análisis , Inmunohistoquímica , Datos de Secuencia Molecular , Proteína 7B2 Secretora Neuroendocrina , Hormonas Hipofisarias/inmunología , Proteínas Recombinantes de Fusión/genética , Homología de Secuencia de Ácido Nucleico , Xenopus laevis
17.
Anal Biochem ; 165(2): 320-6, 1987 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-3322101

RESUMEN

A heterologous lectin-enzyme immunoassay is described. Microtiter plate wells were coated with affinity-purified antibodies to human transferrin. After incubation with transferrin sialovariants, prepared by limited neuraminidase treatment and separated with chromatofocusing, a lectin-enzyme-streptavidin complex was added. A good correlation was obtained between the number of terminal galactose groups on transferrin and the response in the lectin-enzyme immunoassay using Ricinus communis agglutinin as the galactose-binding lectin. The results indicate that characterization of glycosylation is possible with less than a microgram of the glycoprotein available, using lectin-enzyme immunoassays.


Asunto(s)
Variación Genética , Hemaglutininas , Ácidos Siálicos/análisis , Transferrina/genética , Ensayo de Inmunoadsorción Enzimática , Galectinas , Técnicas para Inmunoenzimas , Inmunoglobulina G , Neuraminidasa , Transferrina/análisis
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