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1.
Br J Cancer ; 109(11): 2864-74, 2013 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-24201754

RESUMEN

BACKGROUND: Prognostic biomarkers aim to improve on the current inadequate method of histological assessment to identify patients with oral epithelial dysplasia at greatest risk of malignant transformation. We aimed to assess the prognostic ability of six protein biomarkers linked to the epidermal growth factor receptor (EGFR) pathway, including three tetraspanins, in a large multicentre oral dysplasia cohort. METHODS: One hundred and forty-eight cases with varying degrees of epithelial dysplasia underwent immunohistochemical assessment for CD9, CD151, CD82, EGFR, Her-2, and COX-2. Scoring was performed independently by two observers. Univariate analyses using both logistic and Cox regression models and a multivariate regression were performed. RESULTS: Malignant progression was significantly greater in those cases with decreased expression of CD9 (P=0.02), and increased expression of CD151 (P=0.02), EGFR (P=0.04), and COX-2 (P=0.003). Histological grade (P=0.0002) and morphology (P=0.03) were also prognostic, whereas smoking and alcohol were not. The optimal combination by backward-variable selection was of histological grade (hazard ratio (HR) 1.64; 95% CI 1.12, 2.40), COX-2 overexpression (HR 1.12; 1.02, 1.24) and CD9 underexpression (HR 0.88; 0.80, 0.97). CD82 and Her-2 demonstrated no prognostic ability. CONCLUSION: This is the first study of the expression and prognostic potential of the tetraspanins in oral dysplasia. A combination of certain biomarkers with clinical factors appeared to improve the accuracy of determining the risk of malignancy in individuals with oral dysplasia. These findings may also offer potential new therapeutic approaches for this condition.


Asunto(s)
Ciclooxigenasa 2/metabolismo , Receptores ErbB/metabolismo , Neoplasias de la Boca/diagnóstico , Neoplasias Glandulares y Epiteliales/diagnóstico , Tetraspanina 24/metabolismo , Tetraspanina 29/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Transformación Celular Neoplásica/metabolismo , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/metabolismo , Neoplasias Glandulares y Epiteliales/metabolismo , Lesiones Precancerosas/diagnóstico , Lesiones Precancerosas/metabolismo , Lesiones Precancerosas/patología , Pronóstico , Estudios Retrospectivos , Adulto Joven
2.
Ann Oncol ; 24(1): 179-85, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22865778

RESUMEN

BACKGROUND: The intra-tumor stroma percentage in colon cancer (CC) patients has previously been reported by our group as a strong independent prognostic parameter. Patients with a high stroma percentage within the primary tumor have a poor prognosis. PATIENTS AND METHODS: Tissue samples from the most invasive part of the primary tumor of 710 patients (52% Stage II, 48% Stage III) participating in the VICTOR trial were analyzed for their tumor-stroma percentage. Stroma-high (>50%) and stroma-low (≤50%) groups were evaluated with respect to survival times. RESULTS: Overall and disease-free survival times (OS and DFS) were significantly lower in the stroma-high group (OS P<0.0001, hazard ratio (HR)=1.96; DFS P<0.0001, HR=2.15). The 5-year OS was 69.0% versus 83.4% and DFS 58.6% versus 77.3% for stroma-high versus stroma-low patients. CONCLUSION: This study confirms the intra-tumor stroma ratio as a prognostic factor. This parameter could be a valuable and low cost addition to the TNM status and next to current high-risk parameters such as microsatellite instability status used in routine pathology reporting. When adding the stroma-parameter to the ASCO criteria, the rate of 'undertreated' patients dropped from 5.9% to 4.3%, the 'overtreated' increased with 6.8% but the correctly classified increased with an additional 14%.


Asunto(s)
Neoplasias del Colon/patología , Células del Estroma/patología , Método Doble Ciego , Humanos , Pronóstico , Análisis de Supervivencia
3.
Clin Otolaryngol ; 35(5): 364-72, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21108746

RESUMEN

BACKGROUND: Laryngeal dysplasia is a pre-malignant condition with wide variability in rates of malignant transformation reported in the literature. The management and follow-up strategies of these lesions vary widely. OBJECTIVES: To assess the risk of and interval to malignant transformation in patients with laryngeal dysplasia, the effect of different treatment modalities on malignant transformation and the effects that risk factors such as smoking, excessive alcohol intake and histological grade may have on this. TYPE OF REVIEW: Systematic of observational studies with attempted meta-analysis. SEARCH STRATEGY: A structured search of Medline (1966 to January 2010), EMBASE (1980 to January 2010), CINAHL (1981 to January 2010) and Cochrane databases (CENTRAL, Cochrane Library, 1995 to January 2010). RESULTS: Nine hundred and forty cases from nine studies were included in the analysis. Overall malignant transformation rate was 14% (confidence interval 8, 22) and mean time to malignant transformation was 5.8 years. The malignant transformation rate is higher with increased severity of dysplasia grade - severe/CIS 30.4%versus mild/moderate 10.6% (P < 0.0002). Treatment modality did not show significant effects. CONCLUSIONS: Laryngeal dysplasia carries a significant risk of malignant transformation. This risk triples with increasing severity of dysplasia. Transformation often occurs late and is not related to the grade of dysplasia. There is little evidence, therefore, to support the early discharge of patients with mild/moderate dysplasia, which is practised by some clinicians.


Asunto(s)
Transformación Celular Neoplásica , Neoplasias Laríngeas/patología , Lesiones Precancerosas/patología , Humanos , Neoplasias Laríngeas/terapia , Lesiones Precancerosas/terapia , Riesgo
4.
Clin Oncol (R Coll Radiol) ; 20(2): 176-83, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18248971

RESUMEN

AIMS: With the aim of improving locoregional control, the use of preoperative chemoradiotherapy (CRT) for rectal cancer has increased. A pathological complete response (pCR) is often used as a surrogate marker for the efficacy of different CRT schedules. By analysing factors affecting pCR, this analysis aims to guide the development of future trials. MATERIALS AND METHODS: Searches of Medline, EMBASE and the electronic American Society of Clinical Oncology abstract databases were carried out to identify prospective phase II and phase III trials using preoperative CRT to treat rectal cancer. Trials were eligible for inclusion if they defined: the CRT drugs, the radiation dose and the pCR rate. Phase I patients were excluded from the analysis. A multivariate analysis examined the effect of the above variables on the pCR rate and in addition the use of neoadjuvant chemotherapy, the type of publication (peer reviewed vs abstract), the year of publication and whether the cancers were stated to be inoperable, fixed or threatening the circumferential resection margin were included. The method of analysis used was weighted linear modelling of the pCR rate. RESULTS: Sixty-four phase II and seven phase III trials were identified including a total of 4732 patients. Statistically significant factors associated with pCR were the use of two drugs, the method of fluoropyrimidine administration (with continuous intravenous 5-fluorouracil being the most effective) and a higher radiotherapy dose. Although the use of two drugs was associated with a higher rate of pCR, no single schedule seemed to be more effective. None of the other factors analysed significantly influenced pCR. CONCLUSIONS: A higher rate of pCR is seen in studies using two drugs, infusional 5-fluorouracil and a radiotherapy dose of 45 Gy and above.


Asunto(s)
Quimioterapia Adyuvante , Fluorouracilo/uso terapéutico , Radioterapia Adyuvante , Neoplasias del Recto/tratamiento farmacológico , Neoplasias del Recto/radioterapia , Protocolos de Quimioterapia Combinada Antineoplásica , Ensayos Clínicos Fase II como Asunto , Ensayos Clínicos Fase III como Asunto , Terapia Combinada , Bases de Datos Bibliográficas , Relación Dosis-Respuesta en la Radiación , Humanos , Análisis Multivariante , Terapia Neoadyuvante , Resultado del Tratamiento
5.
Clin Otolaryngol ; 33(3): 210-22, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18559026

RESUMEN

OBJECTIVES: This review examines the effectiveness of positron emission tomography (PET) in the detection of recurrent or persistent head and neck squamous cell carcinoma after radiotherapy or chemoradiotherapy. DESIGN: A systematic review and meta-analysis of trials of PET for detecting residual/recurrent head and neck squamous cell carcinoma treated by radiotherapy or chemoradiotherapy. Trials were quality assessed using the Quality Assessment of Diagnostic Accuracy Studies tool for assessing diagnostic accuracy studies. Quantitative data were extracted and a bivariate random effects model used to calculate pooled sensitivity and specificity. SETTING: Tertiary referral head and neck centre. PARTICIPANTS: Prospective and retrospective studies, excluding reviews, which included patients with head and neck squamous cell carcinoma who had fluorodeoxyglucose PET in the post-treatment phase following primary treatment by radiotherapy or chemoradiotherapy. MAIN OUTCOMES MEASURES: Quality assessment, sensitivity, specificity, false positive rates, false negative rates, positive and negative predictive values. RESULTS: Twenty-seven of 1871 identified studies were eligible for inclusion. The pooled sensitivity and specificity of PET for detecting residual or recurrent head and neck squamous cell carcinoma were 94% [95% confidence interval (CI), 87-97%] and 82% (95% CI, 76-86%) respectively. Positive and negative predictive values were 75% (95% CI, 68-82%), and 95% (95% CI, 92-97%) respectively. Sensitivity was greater for scans performed 10 weeks or more after treatment. CONCLUSIONS: Positron emission tomography is highly accurate in this role. However it is less sensitive early after treatment and has poor anatomical detail. PET may reduce the requirement for check endoscopies and planned neck dissections. A protocol for its use in post-treatment surveillance is proposed.


Asunto(s)
Carcinoma de Células Escamosas/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Tomografía de Emisión de Positrones , Carcinoma de Células Escamosas/terapia , Terapia Combinada , Estudios de Seguimiento , Neoplasias de Cabeza y Cuello/terapia , Humanos , Recurrencia Local de Neoplasia/diagnóstico por imagen , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad
6.
Clin Oncol (R Coll Radiol) ; 19(5): 356-62, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17399963

RESUMEN

AIMS: To examine cancer patients' and carers' use of, and attitudes to, the Internet as an information source compared with other media. MATERIALS AND METHODS: The study was carried out in two phases: in phase I, interviews were used to construct a suitable instrument. In phase II, interviews were completed with 800 recently diagnosed patients and 200 carers. RESULTS: Relatively few patients (4.8%), but a high proportion of carers (48%), accessed the Internet directly for cancer information. However, around half of the patients used Internet information provided by someone else, generally a family member. The use of Internet information was uniformly low among ethnic minorities. Those who accessed Internet information reported high levels of satisfaction and generally rated it higher than booklets or leaflets. When asked who they would like to provide Internet information, overwhelmingly patients wanted the hospital doctor to do so. When this was done, there was very high compliance. Carers were much more proactive information seekers than patients. CONCLUSIONS: The Internet is an effective means of information provision in those who use it. Facilitated Internet access and directed use by health professionals would be effective ways of broadening access to this medium.


Asunto(s)
Cuidadores , Internet , Neoplasias/psicología , Educación del Paciente como Asunto , Adulto , Anciano , Anciano de 80 o más Años , Pueblo Asiatico , Actitud hacia los Computadores , Familia , Femenino , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Neoplasias/etnología , Relaciones Profesional-Familia
7.
Eur J Cancer ; 85: 6-14, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28881249

RESUMEN

BACKGROUND: A recent large United Kingdom (UK) clinical trial demonstrated that positron-emission tomography-computed tomography (PET-CT)-guided administration of neck dissection (ND) in patients with advanced head and neck cancer after primary chemo-radiotherapy treatment produces similar survival outcomes to planned ND (standard care) and is cost-effective over a short-term horizon. Further assessment of long-term outcomes is required to inform a robust adoption decision. Here we present results of a lifetime cost-effectiveness analysis of PET-CT-guided management from a UK secondary care perspective. METHODS: Initial 6-month cost and health outcomes were derived from trial data; subsequent incidence of recurrence and mortality was simulated using a de novo Markov model. Health benefit was measured in quality-adjusted life years (QALYs) and costs reported in 2015 British pounds. Model parameters were derived from trial data and published literature. Sensitivity analyses were conducted to assess the impact of uncertainty and broader National Health Service (NHS) and personal social services (PSS) costs on the results. RESULTS: PET-CT management produced an average per-person lifetime cost saving of £1485 and an additional 0.13 QALYs. At a £20,000 willingness-to-pay per additional QALY threshold, there was a 75% probability that PET-CT was cost-effective, and the results remained cost-effective over the majority of sensitivity analyses. When adopting a broader NHS and PSS perspective, PET-CT management produced an average saving of £700 and had an 81% probability of being cost-effective. CONCLUSIONS: This analysis indicates that PET-CT-guided management is cost-effective in the long-term and supports the case for wide-scale adoption.


Asunto(s)
Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/economía , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/economía , Costos de la Atención en Salud , Tomografía Computarizada por Tomografía de Emisión de Positrones/economía , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/terapia , Quimioradioterapia Adyuvante/economía , Simulación por Computador , Ahorro de Costo , Análisis Costo-Beneficio , Técnicas de Apoyo para la Decisión , Femenino , Neoplasias de Cabeza y Cuello/mortalidad , Neoplasias de Cabeza y Cuello/terapia , Humanos , Masculino , Cadenas de Markov , Modelos Económicos , Disección del Cuello/economía , Terapia Neoadyuvante/economía , Valor Predictivo de las Pruebas , Años de Vida Ajustados por Calidad de Vida , Atención Secundaria de Salud/economía , Carcinoma de Células Escamosas de Cabeza y Cuello , Medicina Estatal/economía , Factores de Tiempo , Resultado del Tratamiento , Reino Unido
8.
Clin Oncol (R Coll Radiol) ; 18(1): 38-45, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16477918

RESUMEN

AIMS: A recent meta-analysis has shown a survival advantage for the addition of concurrent chemotherapy to radiotherapy in the treatment of cervical carcinoma. Controversy persists about the most appropriate chemotherapy schedule and whether similar results for tumour control and toxicity may be achieved with optimally delivered radiotherapy. A single-centre experience of a concurrent chemotherapy regimen is presented. MATERIALS AND METHODS: All women treated with concurrent chemoradiotherapy at a university hospital from 1 January 1999 to 1 May 2002 were identified. Acute and late complications were scored using the National Cancer Institute Common Toxicity Criteria and RTOG/ EORTC system, respectively. Univariate and multivariate analyses were carried out to examine the relationship between demographics, stage, overall treatment time, radiotherapy dose, selectron insertion, number of chemotherapy cycles and occurrence of acute and late toxicity. RESULTS: Seventy-nine women received concurrent weekly cisplatin (40 mg/m2) with radiotherapy. Thirty-eight per cent had early tumours (FIGO IIA or less) and 62% had locally advanced tumours. Twenty-eight per cent of women had surgery as part of primary treatment. Radiation technique included external-beam pelvic radiotherapy (EBRT) (45-50.4 Gy in 25-28 fractions) and medium-dose rate brachytherapy single insertion (25-27 Gy to point A) or EBRT alone. Median overall treatment time was 49 days (range 23-91 days). Three-year survival rate was 87% (95% confidence interval [CI] 79-95%). Three-year, progression-free survival rate was 75% (95% CI 65-85%). At a median follow-up of 35 months: 27 (34%) women experienced 45 episodes of acute grade 3 or 4, and eight women (10%) experienced 12 late grade 3 or 4 complications. CONCLUSIONS: Weekly cisplatin 40 mg/m2 concurrent with radiotherapy is well tolerated when given to an unselected population of patients. Survival rates seem to be excellent, with both local control and overall survival being at least as good as those in published randomised trials.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Cisplatino/uso terapéutico , Neoplasias del Cuello Uterino/tratamiento farmacológico , Adenocarcinoma/mortalidad , Adenocarcinoma/radioterapia , Adulto , Anciano , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/radioterapia , Terapia Combinada , Femenino , Humanos , Persona de Mediana Edad , Análisis Multivariante , Metástasis de la Neoplasia , Recurrencia Local de Neoplasia , Estadificación de Neoplasias , Traumatismos por Radiación/etiología , Radioterapia/efectos adversos , Estudios Retrospectivos , Análisis de Supervivencia , Neoplasias del Cuello Uterino/mortalidad , Neoplasias del Cuello Uterino/radioterapia
9.
Aliment Pharmacol Ther ; 21(4): 479-84, 2005 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-15710000

RESUMEN

INTRODUCTION: With the rising incidence of oesophageal cancer, palliative treatment has an increasingly important role. With median survival unlikely to exceed 6 months, in advanced disease the palliative therapy chosen must not hasten patient's demise. AIM: To establish the outcome of both modern and historical palliative treatment in oesophageal tumours, with emphasis on the aetiology and outcome of iatrogenic perforation. METHODS: Patients with oesophageal or cardia carcinoma treated within the West Midlands between 1992 and 1996 were identified retrospectively. Information was gathered from hospital case notes and the regional cancer intelligence unit with hospitals visited to capture data. All episodes were entered into a dedicated database. RESULTS: Of the 3660 patients who were treated, 2529 received palliation as primary treatment, with 5259 palliative procedures performed; 164 iatrogenic perforations were recorded; 83 were due to diagnostic endoscopy (endoscopic perforation) with the reminder due to interventional palliative procedures. Median survival from all forms of palliation was 138 days. Following perforation survival was 95 days after interventional palliative procedure and 58 days after endoscopic perforation (P > 0.05). Thirty-day mortality after emergency surgery was 11.8% with mean survival of 7.5 months. CONCLUSION: Perforation at diagnostic endoscopy is associated with substantial mortality despite rapid intervention. Patients with suspected cancer must be investigated with extreme care to reduce iatrogenic complications.


Asunto(s)
Cardias , Neoplasias Esofágicas/terapia , Perforación del Esófago/etiología , Cuidados Paliativos , Neoplasias Gástricas/terapia , Anciano , Perforación del Esófago/terapia , Esofagoscopía/efectos adversos , Femenino , Humanos , Masculino , Auditoría Médica , Persona de Mediana Edad , Estudios Retrospectivos , Análisis de Supervivencia
10.
Br J Radiol ; 78(934): 934-8, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16177017

RESUMEN

Pathological complete response (pCR) has been used as a marker for the efficacy of pre-operative chemoradiotherapy (CRT) schedules in rectal cancer. To date there have been no randomized trials comparing CRT regimens in rectal cancer. Prospective phase II and CRT arms of randomized trials reported up to January 2004 were included, providing they defined the following minimum variables: drugs employed during CRT, radiotherapy dose and pCR rate. Multivariate analysis was used to examine the relationship of these variables on the pCR rate. In addition, the use of neoadjuvant chemotherapy, the type of publication (peer reviewed vs meeting abstract) and whether the tumours were stated to be unresectable/clinically fixed or to have threatened circumferential margins were investigated. The method of analysis was weighted linear modelling of the pCR rate which was normalized by the arcsine transformation. Phase II and phase III trials were identified including a total of 3157 patients. On multivariate analysis only the use of continuous infusion 5FU (p = 0.01), the use of a second drug (p = 0.001) and radiation dose (p = 0.02) were associated with higher rates of pCR. The use of a two drug regimen, the mode of delivery of 5FU and the radiation dose appear to be related to the incidence of pCR following CRT for rectal cancer. These results may generate hypotheses for future randomized trials. Important factors not considered in this analysis include the variability in pathological examination and in the time interval between CRT and surgery. In addition, the toxicity of the CRT regimens requires further investigation.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias del Recto/tratamiento farmacológico , Neoplasias del Recto/radioterapia , Ensayos Clínicos Fase II como Asunto , Ensayos Clínicos Fase III como Asunto , Relación Dosis-Respuesta a Droga , Fluorouracilo/administración & dosificación , Humanos , Análisis Multivariante , Cuidados Preoperatorios/métodos , Profármacos , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto , Neoplasias del Recto/patología , Resultado del Tratamiento
11.
Endocrinology ; 115(5): 1678-82, 1984 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-6541569

RESUMEN

The present studies examined the effects of forskolin on the PTH responsive adenylate cyclase system of canine basolateral renal cortical membranes. This agent is a potent activator of adenylate cyclase in a wide variety of intact cells and broken cell preparations. Initially forskolin was believed to activate adenylate cyclase by direct stimulation of the catalytic unit of the enzyme. Several observations, however, have suggested that there may be additional noncatalytic sites of action. In the present studies, forskolin was found to increase PTH-stimulated adenylate cyclase activity by 4-fold associated with a 2-fold decrease in the Kact for PTH (dose of PTH required for half-maximal enzyme stimulation). Studies of the interaction of forskolin with magnesium revealed that forskolin resulted in a dose dependent increase in the affinity of adenylate cyclase for magnesium. A short lag was observed in the onset of enzyme activation by forskolin. The lag was decreased as Mg++ concentration was increased. The forskolin-induced increase in the affinity for Mg++ was similar to that produced by other activators of adenylate cyclase such as NaF and GTP, which interact with the nucleotide regulatory protein. Magnesium also markedly affected the affinity of the enzyme system for forskolin. Kact for forskolin was reduced from 10 microM to 0.1 microM as Mg++ concentration was raised from 0.5 mM to 40 mM. Since previous studies have shown that the allosteric effects of Mg++ are at, or closely related to, the nucleotide regulatory protein, these findings suggest that forskolin may also affect this site. In summary, in basolateral renal cortical membrane of canine kidney the effects of forskolin to increase the affinity of adenylate cyclase for PTH and to alter the allosteric effects of Mg++ on enzyme activity are indicative of noncatalytic effects of forskolin. The interpretation of action of forskolin on adenylate cyclase activity should not be restricted to direct stimulation of the catalytic unit.


Asunto(s)
Adenilil Ciclasas/metabolismo , Antihipertensivos/farmacología , Diterpenos/farmacología , Corteza Renal/enzimología , Riñón/enzimología , Hormona Paratiroidea/farmacología , Animales , Membrana Celular/enzimología , Colforsina , Perros , Activación Enzimática , Cinética , Magnesio/farmacología
12.
Endocrinology ; 131(5): 2161-4, 1992 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1330493

RESUMEN

Structural modifications of the amino-terminal region of PTH resulted in the generation of PTH analogs with potent antagonist activities and markedly reduced agonist activities. Further development of these structure-function relationships to modifications of the sequence of the PTH-related protein (PTHrP) resulted in PTH/PTHrP antagonist analogs with increased antagonist activity and little if any agonist effects. Since studies from our laboratory have shown that measurement of protein kinase-A activity appears to be a more sensitive index of the actions of PTH than measurements of total cAMP, the present studies were designed to examine the effects of a series of PTHrP-based peptides for agonist/antagonist effects in opossum kidney (OK) cells. The results show that PTHrP-(7-34)NH2, which does not increase cAMP, displays agonist activity in terms of increasing protein kinase-A activity. Furthermore, [Leu11,D-Trp12]PTHrP-(7-34)NH2 and [D-Trp12]PTHrP-(7-34)NH2, which appear to be effective antagonists of rat PTH-(1-34)-stimulated cAMP generation, were less effective in antagonizing the effects on protein kinase-A and only [Leu11,D-Trp12] PTHrP-(7-34)NH2 appeared to exhibit any antagonist activity. The Ki for [Leu11,D-Trp1/]PTHrP-(7-34)NH2 to antagonize the stimulatory effect of 1 nM rat PTH-(1-34) was easily demonstrable by measurements of cAMP, but could not be demonstrated using the assay of protein kinase-A activity. These data underscore the observation that measurement of protein kinase-A is a more sensitive index of the effects of PTH than measurements of cAMP and that significant agonist activity on the cAMP/protein kinase pathway cannot be excluded without measurements of protein kinase-A activity.


Asunto(s)
Riñón/citología , Fragmentos de Péptidos/farmacología , Proteínas Quinasas/fisiología , Proteínas/farmacología , Animales , Células Cultivadas , AMP Cíclico/análisis , AMP Cíclico/metabolismo , AMP Cíclico/fisiología , Activación Enzimática/fisiología , Riñón/química , Riñón/enzimología , Zarigüeyas , Proteínas Quinasas/metabolismo
13.
Endocrinology ; 125(1): 295-301, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2544405

RESUMEN

Current evidence indicates that signal transduction after receptor binding of PTH involves the stimulation of adenylate cyclase as well as stimulation of phosphoinositide metabolism. Recent studies, showing that PTH alters phosphate transport in opossum kidney cells at concentrations which do not increase cAMP production and that activators of protein kinase-C also alter phosphate transport, have led to the suggestion that there is a dual mechanism for the regulation of phosphate transport by PTH, namely, protein kinase-C at physiological levels of PTH and cAMP at higher levels of PTH. The present studies were designed to evaluate the relationship between cAMP-dependent protein kinase (PK-A), a more sensitive indicator of alterations in cAMP metabolism than measurements of total cellular cAMP, and phosphate transport in opossum kidney cells, in response to bovine (b)PTH 1-34 and [Nle8,Nle18,Tyr34]bPTH 3-34 amide. While bPTH 1-34 markedly stimulated cAMP accumulation (half-maximal stimulation between 1 and 10 nM), PTH 3-34 analog did not. Phosphate transport was inhibited in a dose-dependent manner by bPTH 1-34, with half-maximal effect occurring between 0.1 and 1 nM. [Nle8,Nle18,Tyr34]bPTH 3-34 amide also altered phosphate transport, although this peptide was 3 orders of magnitude less potent than bPTH 1-34. PK-A activity increased in response to bPTH 1-34 and correlated closely with the effects of PTH on phosphate transport. [Nle8,Nle18,Tyr34]bPTH 3-34 amide, which did not appear to increase cAMP, also resulted in a significant increase in the activity of PK-A. Studies of inhibition of cAMP accumulation using 2',5'-dideoxyadenosine demonstrated that while this agent markedly inhibited the accumulation of cAMP in response to PTH, the effects of PTH on phosphate transport were not altered. However, in spite of the reduction in cAMP the activation of PK-A was similar to control. These data indicate that the effects of PTH peptides on phosphate transport are more closely related to changes in the activity of PK-A than to levels of total cAMP. Activation of PK-A in response to PTH is demonstrable at the lowest doses of PTH that alter phosphate transport.


Asunto(s)
Didesoxiadenosina/análogos & derivados , Riñón/metabolismo , Hormona Paratiroidea/farmacología , Fosfatos/metabolismo , Proteínas Quinasas/metabolismo , Animales , Transporte Biológico/efectos de los fármacos , Células Cultivadas , AMP Cíclico/metabolismo , Didesoxinucleósidos/farmacología , Riñón/citología , Zarigüeyas , Fragmentos de Péptidos/farmacología
14.
Endocrinology ; 117(4): 1456-61, 1985 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-4029088

RESUMEN

It is known that the secretion of PTH is often impaired in association with aluminum (Al3+) accumulation in patients with renal failure. The mechanisms involved remain ill defined. Since adenylate cyclase plays a role in the regulation of PTH secretion, these studies examine the effects of Al3+ on parathyroid adenylate cyclase. In membranes from normal bovine parathyroid glands, basal adenylate cyclase activity, in the presence of 0.2 mM ATP and 20 mM Mg2+, increased by 22% as Al3+ was raised from 0-10 microM. Higher Al3+ concentrations caused a progressive decrease in adenylate cyclase activity, reaching 68% inhibition of control activity at 2 mM Al3+. Since adenylate cyclase activation is influenced by the interaction of multiple sites within the adenylate cyclase complex, the nature of the inhibition by Al3+ was explored by examining the interaction of Al3+ with substrate ATP and with Mg2+, an allosteric activating metal ion. In the presence of 20 mM Mg2+, Al3+ concentrations of 1-2 mM resulted in noncompetitive inhibition with respect to ATP [decrease in maximum velocity (Vmax) from 4176 in the absence of Al3+ to 1106 pmol cAMP/mg protein X 15 min; Michaelis Menten constant (Km) for ATP was unchanged]. In contrast, at fixed ATP (0.2 mM), 0.5 mM resulted in competitive inhibition of adenylate cyclase with respect to Mg2+, whereas at higher Al3+ concentrations the inhibition was noncompetitive. When Mg2+ was replaced by Mn2+ (enzyme activity reflects the activity of the catalytic unit), the inhibitory effect of Al3+ on adenylate cyclase activity was abolished. These data suggest that the inhibition of parathyroid adenylate cyclase by Al3+ occurs at the level of the allosteric metal activating site. These data provide a potential mechanism for the inhibition of PTH secretion by Al3+.


Asunto(s)
Adenilil Ciclasas/metabolismo , Compuestos de Aluminio , Aluminio/farmacología , Cloruros , Glándulas Paratiroides/enzimología , Adenosina Trifosfato/metabolismo , Cloruro de Aluminio , Animales , Cloruro de Calcio/farmacología , Bovinos , Guanosina Trifosfato/metabolismo , Cinética , Magnesio/metabolismo , Manganeso/metabolismo , Glándulas Paratiroides/efectos de los fármacos
15.
Endocrinology ; 134(4): 1733-7, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8137737

RESUMEN

PTH administration in vivo increases osteoblast number and activity, resulting in increased bone formation, and also increases osteoclast-mediated bone resorption. Studies in vitro, however, have shown that the actions of PTH on osteoblast-like cells are inhibitory and catabolic, as shown by decreases in growth rate and collagen synthesis and increases in collagenase production. The present studies were designed to investigate possible mechanisms for these observations by examining the effects of PTH on the response of osteoblast-like cells to the osteoblast growth factor, epidermal growth factor (EGF). Confluent cultures of UMR 106-01 cells were treated with rat PTH-(1-34) for periods up to 72 h, and EGF receptors were measured with [125I]EGF. PTH, in a dose- and time-dependent manner, increased the number of EGF receptors 2-fold. The half-maximal effect of PTH occurred at a concentration of 1 nM, the same PTH concentration that resulted in half-maximal increases in cAMP generation. The increase in EGF binding was associated with an enhanced biological effect, as shown by augmentation of EGF-stimulated diglyceride production. The effect of PTH could be reproduced by the addition of 8-bromo-cAMP, but not by the phorbol ester phorbol myristate acetate. In the presence of cyclohexamide, the effect of PTH on EGF binding was abolished, suggesting that new protein synthesis was required to increase the number of EGF receptors. Northern blots of total RNA, using a cDNA probe encoding the extracellular domain of the rat EGF receptor, revealed that PTH treatment resulted in a 2- to 3-fold increase in the level of EGF receptor mRNA. These data suggest that the proliferative effects of PTH on the osteoblast may be mediated indirectly by a PTH-induced increase in the number of EGF receptors.


Asunto(s)
Receptores ErbB/metabolismo , Osteoblastos/metabolismo , Hormona Paratiroidea/farmacología , Animales , Unión Competitiva , División Celular/efectos de los fármacos , AMP Cíclico/análogos & derivados , AMP Cíclico/fisiología , Cicloheximida/farmacología , Relación Dosis-Respuesta a Droga , Factor de Crecimiento Epidérmico/metabolismo , Receptores ErbB/efectos de los fármacos , Receptores ErbB/genética , Osteoblastos/efectos de los fármacos , Osteoblastos/patología , Proteína Quinasa C/metabolismo , ARN Mensajero/metabolismo , Ratas , Sistemas de Mensajero Secundario/fisiología , Factores de Tiempo , Células Tumorales Cultivadas
16.
Endocrinology ; 134(1): 331-6, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7506208

RESUMEN

Although PTH is known to stimulate both the adenylate cyclase/protein kinase-A system and the phospholipase-C/protein kinase-C second messenger systems, the relative roles of these second messenger pathways remain unclear. The present studies were designed to examine the effect of triamcinolone on PTH-stimulated second messenger systems and phosphate transport in confluent cultures of opossum kidney cells. Triamcinolone was added to these cultures at a concentration of 10 nM for 24-48 h. Neither cell number nor protein content was changed by this treatment. The addition of triamcinolone did not alter PTH receptor binding or competitive displacement radioligand binding assay curves. PTH-stimulated cAMP generation and activation of protein kinase-A were not altered by triamcinolone. The glucocorticoid, however, increased basal phosphate uptake from 1.0 +/- 0.1 to 1.28 +/- 0.1 pmol/5 min.culture (P < 0.01). Phosphate transport was significantly decreased by PTH (0.01 nM) in the triamcinolone-treated cultures, but not in control cultures. Phosphate uptake in the presence of maximal doses of PTH was similar in both control and triamcinolone-treated cultures. Thus, the PTH-responsive component of phosphate transport was preserved, and the threshold dose for the effect of PTH was reduced after treatment with triamcinolone. Studies were then performed to evaluate the alternate second messenger pathway. In control cultures, PTH rapidly increased the level of diglyceride mass, as measured by diglyceride kinase assay, from 0.18 +/- 0.01 to a peak of 0.26 +/- 0.02 mol/100 mol total phospholipid (P < 0.002), 1 min after addition of the hormone. Triamcinolone pretreatment for 48 h, however, elevated the basal diglyceride levels, but the increase after the addition of PTH was totally abolished. The absence of an increase in diglyceride upon stimulation with PTH correlated with elimination of the PTH-stimulated increase in the activity of particulate protein kinase-C. Thus, in triamcinolone-treated cells, the effect of PTH on phosphate transport was preserved, and the threshold dose of PTH-induced alteration in phosphate transport was reduced in the absence of stimulation of this alternate second messenger pathway. These data show that triamcinolone in opossum kidney cells does not alter PTH activation of the cAMP/protein kinase-A system, but eliminates the increase in diglyceride and the activation of protein kinase-C in response to PTH. These studies emphasize the major role of the protein kinase-A system in the regulation of phosphate transport by PTH.


Asunto(s)
Riñón/metabolismo , Hormona Paratiroidea/farmacología , Fosfatos/metabolismo , Sistemas de Mensajero Secundario/efectos de los fármacos , Triamcinolona/farmacología , 1-Metil-3-Isobutilxantina/farmacología , Animales , Transporte Biológico/efectos de los fármacos , Línea Celular , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Diglicéridos/biosíntesis , Riñón/citología , Zarigüeyas , Proteína Quinasa C/metabolismo , Valores de Referencia
17.
Br J Surg ; 87(3): 362-73, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10718965

RESUMEN

Aims: To inform the debate about upper gastrointestinal cancer care in the UK, the incidence of cancer of the oesophagus and cardia (OGJ) was determined in the West Midlands, a region covering 10 per cent of England and Wales, with particular reference to the methods of treatment. METHODS: The case-notes of 2776 patients diagnosed with oesophageal and OGJ cancer in the 5 years from 1 January 1992 to 31 December 1996 were scrutinized by one experienced surgeon. Tumour types were classified by histology and site, and treatment modalities assessed for 30-day mortality rate together with life-table analyses. RESULTS: Oesophageal cancer was identified in 2188 patients (61 per cent lower, 34 per cent middle, 4 per cent upper), including 999 squamous carcinomas (27 per cent lower, 64 per cent middle, 9 per cent upper) and 995 adenocarcinomas (97 per cent lower, 3 per cent middle), while there were 588 cases of OGJ cancer (94 per cent adenocarcinomas). Resection was the commonest treatment (865 cases; 31 per cent), with a mortality rate of 10 per cent for oesophageal and 4 per cent for OGJ cancer. Palliative resection had a higher mortality rate than radiotherapy (9 versus 3 per cent), compared with 22 per cent for endoscopic palliation, while the 30-day mortality rate was 30 per cent for the 308 patients given no treatment. CONCLUSIONS: Squamous carcinomas and adenocarcinomas of the oesophageal body are now equally common; lower-third and OGJ tumours are predominantly adenocarcinomas. This study provides baseline data for critical appraisal of potential changes in the delivery of upper gastrointestinal cancer in the UK.

18.
Bone Marrow Transplant ; 34(5): 399-403, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15273706

RESUMEN

We conducted a prospective randomised study to compare the efficiency of out-patient progenitor cell mobilisation using either intermediate-dose cyclophosphamide (2 g/m(2)) and lenograstim at 5 micrograms/kg (Cyclo-G-CSF group, n=39) or lenograstim alone at 10 micrograms/kg (G-CSF group, n=40). The end points were to compare the impact of the two regimens on mobilisation efficiency, morbidity, time spent in hospital, the number of apheresis procedures required and engraftment kinetics. Successful mobilisation was achieved in 28/40 (70%) in the G-CSF group vs 22/39 (56.4%) for Cyclo-G-CSF (P=0.21). The median number of CD34+ cells mobilised was 2.3 x 10(6)/kg and 2.2 x 10(6)/kg for G-CSF and cyclo-G-CSF arms following a median of two apheresis procedures. Nausea and vomiting and total time spent in the hospital during mobilisation were significantly greater after Cyclo-G-CSF (P<0.05). Rapid neutrophil and platelet engraftment was achieved in all transplanted patients in both groups. In conclusion, G-CSF at 10 micrograms/kg was as efficient at mobilising progenitor cells as a combination of cyclophosphamide and G-CSF with reduced hospitalisation and side effects and prompt engraftment. When aggressive in-patient cytoreductive regimens are not required to both control disease and generate progenitor cells, the use of G-CSF alone appears preferable to combination with intermediate-dose cyclophosphamide.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Ciclofosfamida/administración & dosificación , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Neoplasias Hematológicas/terapia , Movilización de Célula Madre Hematopoyética , Trasplante de Células Madre Hematopoyéticas , Inmunosupresores/administración & dosificación , Proteínas Recombinantes/administración & dosificación , Adulto , Anciano , Eliminación de Componentes Sanguíneos , Quimioterapia Combinada , Femenino , Rechazo de Injerto/tratamiento farmacológico , Humanos , Lenograstim , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento
19.
QJM ; 92(8): 451-4, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10627861

RESUMEN

We retrospectively analysed pregnancy complicated by diabetic nephropathy in patients attending a University teaching hospital (1990-97), to examine fetal/maternal outcomes. Fetal outcomes included early intrauterine deaths, stillbirths, neonatal/perinatal mortality, size for gestational age, malformations, and need for neonatal unit care. Maternal outcomes included change in frequency of hypertension or severe proteinuria, serum creatinine data, and caesarean section rate. There were 21 pregnancies in 18 women, resulting in 21 live infants. Neonatal mortality (RR 10, 95% CI 0-3.9), perinatal mortality (RR 5, 95% CI 0-3.3) and congenital malformations (RR 5.0, 95% CI 0.3-26.3) were greater than in the background population. At delivery, 76% of babies were appropriate in size for gestational age; 57% were preterm, all of whom required neonatal unit care. The caesarean section rate was 90.5% vs. 20% in the background population (RR 4.5, 95% CI 3.4-5.0) (p < 0.05). Hypertension frequency (p < 0.001) and high-grade proteinuria (p < 0.05) increased from booking to delivery. Although the take-home baby rate was 90%, perinatal/neonatal mortality, congenital malformations and caesarean sections, in addition to maternal morbidity, were significantly higher in women with diabetic nephropathy than in the background population.


Asunto(s)
Diabetes Mellitus Tipo 1/complicaciones , Nefropatías Diabéticas/complicaciones , Complicaciones del Trabajo de Parto , Embarazo en Diabéticas/complicaciones , Adulto , Cesárea , Anomalías Congénitas/etiología , Diabetes Mellitus Tipo 1/orina , Nefropatías Diabéticas/orina , Femenino , Muerte Fetal , Edad Gestacional , Humanos , Mortalidad Infantil , Recién Nacido , Recién Nacido Pequeño para la Edad Gestacional , Unidades de Cuidado Intensivo Neonatal , Embarazo , Embarazo en Diabéticas/orina , Estudios Retrospectivos
20.
Eur J Cancer Prev ; 1(3): 265-9, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1467772

RESUMEN

The incidence of cancer of the oesophagus and stomach in the West Midlands region of England have been analysed for the 25 years 1962-86. Overall, cancer of the oesophagus is increasing (from 3.45 per 100,000 in 1962-66 to 4.37 in 1982-86) and stomach cancer is decreasing (19.22 and 16.54 respectively). However, when analysed by histological type and subsite the picture is very different. In oesophagus, squamous cell carcinoma shows only a slight increase whereas for adenocarcinoma the increase is highly significant (from 0.14 to 0.76). In stomach, cardia shows a very similar pattern to adenocarcinoma of oesophagus (increasing from 0.75 to 2.96) but pyloric antrum is decreasing (from 2.63 to 2.32). The rapid changes in investigative procedures over the period have resulted in increasing numbers with histological confirmation and subsite specification but despite these confounding factors, comparative analyses still indicate a real increase in adenocarcinoma of oesophagus and cardia. Although the incidence of both are greater in men than in women, the proportional rates of increase, particularly for cardia, are very similar in both sexes, indicating a common aetiological factor or factors. Analysis by social-economic group reveals that the increases observed are not uniform throughout the population but are relatively higher in professional classes (1 and 2).


Asunto(s)
Adenocarcinoma/epidemiología , Neoplasias Esofágicas/epidemiología , Neoplasias Gástricas/epidemiología , Adenocarcinoma/etiología , Adenocarcinoma/patología , Carcinoma de Células Escamosas/epidemiología , Carcinoma de Células Escamosas/patología , Cardias , Inglaterra/epidemiología , Neoplasias Esofágicas/etiología , Neoplasias Esofágicas/patología , Estudios de Evaluación como Asunto , Femenino , Humanos , Incidencia , Masculino , Vigilancia de la Población , Antro Pilórico , Sistema de Registros , Factores de Riesgo , Factores Sexuales , Factores Socioeconómicos , Neoplasias Gástricas/etiología , Neoplasias Gástricas/patología
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