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1.
Endocr Connect ; 8(6): 672-679, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31035253

RESUMEN

Objective Increased maternal testosterone concentration during pregnancy may affect the fetus. Therefore it is clinically relevant to have a quick and reliable method to determine free testosterone levels. Current calculators for free testosterone are suspected to perform poorly during pregnancy due to suggested competition between high levels of estradiol and free (bio-active) testosterone for sex hormone-binding globulin (SHBG) binding. Therefore, it is claimed that reliable calculation of free testosterone concentration is not possible. However, recent evidence on SHBG-binding sites questions the estradiol effect on the testosterone-SHBG binding during pregnancy. In this study, we investigated whether the free testosterone concentration can be calculated in pregnant women. Design and methods Free testosterone was measured with a specially developed equilibrium dialysis method combined with liquid chromatography tandem mass spectrometry (LC-MS/MS). Free testosterone was also calculated with the formulas of Vermeulen et al. and Ross et al. Results Total and free testosterone measured in healthy men and women were in good agreement with earlier reports. In pregnant women, total testosterone values were higher than in non-pregnant women, whereas free testosterone values were comparable. Calculated free testosterone levels in pregnant women were highly correlated, but marginally higher, compared to measured free testosterone levels. Conclusions We developed an equilibrium dialysis-LC-MS/MS method for the measurement of free testosterone in the low range of pregnant and non-pregnant women. Although during pregnancy total testosterone is increased, this is not the case for free testosterone. The free testosterone formulas perform well in pregnant women.

2.
Sci Rep ; 9(1): 281, 2019 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-30670720

RESUMEN

To understand the ecosystem dynamics that underpin the year-round presence of a large generalist consumer, the Bryde's whale (Balaenoptera edeni brydei), we use a DNA metabarcoding approach and systematic zooplankton surveys to investigate seasonal and regional changes in zooplankton communities and if whale diet reflects such changes. Twenty-four zooplankton community samples were collected from three regions throughout the Hauraki Gulf, New Zealand, over two temperature regimes (warm and cool seasons), as well as 20 samples of opportunistically collected Bryde's whale scat. Multi-locus DNA barcode libraries were constructed from 18S and COI gene fragments, representing a trade-off between identification and resolution of metazoan taxa. Zooplankton community OTU occurrence and relative read abundance showed regional and seasonal differences based on permutational analyses of variance in both DNA barcodes, with significant changes in biodiversity indices linked to season in COI only. In contrast, we did not find evidence that Bryde's whale diet shows seasonal or regional trends, but instead indicated clear prey preferences for krill-like crustaceans, copepods, salps and ray-finned fishes independent of prey availability. The year-round presence of Bryde's whales in the Hauraki Gulf is likely associated with the patterns of distribution and abundance of these key prey items.


Asunto(s)
Código de Barras del ADN Taxonómico/métodos , Dieta , Cadena Alimentaria , Zooplancton/genética , Animales , Balaenoptera , Ecosistema , Nueva Zelanda , Estaciones del Año
3.
Clin Chim Acta ; 432: 72-6, 2014 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-24508625

RESUMEN

Growth hormone (hGH) is a measurand belonging to ISO category 4, indicating intrinsic unavailability of a reference measurement procedure and primary standard material. Large between-method differences have been raising confusion, especially in the interpretation of results of stimulation tests for exclusion of juvenile growth hormone deficiency. Within the framework of the external quality assessment scheme (EQAS) of the SKML (Dutch Foundation for Quality Assessment in Clinical Laboratories), attempts to reduce between-method variation of hGH measurements have been made, starting in 1994 with an inter-laboratory comparison of 9 different immunoassays by using a panel of sera and standard materials available at that time. Methods appeared to differ from each other largely in a systematic, sample-independent manner. These systematic differences are reflected in the hGH measurement results obtained in commutable sera. A commutable serum pool was introduced as a consensus reference material, permitting correction of each method's results to a common scale. Pair wise comparisons ("twin studies") were carried out to investigate and corroborate the effectiveness of this material for harmonization. A significant reduction of the between-laboratory coefficient (CV) of variation from 22 to 9.0% was attained.


Asunto(s)
Análisis Químico de la Sangre/normas , Hormona de Crecimiento Humana/sangre , Humanos , Estándares de Referencia , Análisis de Regresión
4.
Acta Psychiatr Scand ; 126(5): 377-84, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22533798

RESUMEN

OBJECTIVE: The aim of this study was to investigate whether thyroid function and thyroid peroxidase antibodies (TPOAb) are associated with depression, when using both state and trait parameters of depression. METHOD: In 1125 participants of the Nijmegen Biomedical Study, thyroid-stimulating hormone (TSH), free thyroxine (FT4), and TPOAb were measured twice. The Beck Depression Inventory (BDI), a self-reported lifetime diagnosis of depression, and the neuroticism scale of the Eysenck Personality Questionnaire Revised Short Scale (EPQ-RSS) were used to evaluate the presence of state and trait features of depression. RESULTS: We found no association between TSH and FT4 levels and BDI score, current depression, lifetime diagnosis of depression, and EPQ-RSS neuroticism score. Subjects with TPOAb had higher EPQ-RSS neuroticism scores in comparison with subjects without TPOAb, mean score 4.1 vs. 3.2 (regression coefficient 0.70; 95% CI 0.1-1.3; P-value 0.02 after adjustment for confounders). The prevalence of a lifetime diagnosis of depression was higher in subjects with positive TPOAb in comparison with participants without TPOAb: 24.2% vs. 16.7% (relative risk 1.4; 95% CI 1.0-2.1; P-value 0.04 after adjustment for confounders). CONCLUSION: Thyroid peroxidase antibodies are positively associated with trait markers of depression. The presence of TPOAb may be a vulnerability marker for depression.


Asunto(s)
Autoinmunidad , Depresión/epidemiología , Trastorno Depresivo/epidemiología , Glándula Tiroides/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Trastornos de Ansiedad/epidemiología , Autoanticuerpos/sangre , Biomarcadores , Estudios Transversales , Depresión/fisiopatología , Femenino , Humanos , Yoduro Peroxidasa/inmunología , Masculino , Persona de Mediana Edad , Neuroticismo , Pruebas de Función de la Tiroides/estadística & datos numéricos , Glándula Tiroides/inmunología , Tirotropina/sangre , Tiroxina/sangre
5.
Clin Exp Rheumatol ; 29(1): 35-42, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21345290

RESUMEN

OBJECTIVES: To study the effects of antirheumatic drugs on hypothalamic-pituitary-adrenal (HPA) axis activity in patients with rheumatoid arthritis (RA). METHODS: Twenty patients with recent-onset active RA were studied before antirheumatic treatment, after 2 weeks of naproxen, and after 5½ months of additional treatment with sulphasalazine or methotrexate. The results before treatment were compared with those obtained in 20 age and sex-matched healthy controls (HC). Activity of the HPA-axis was assessed under basal conditions and during insulin tolerance tests (ITT). The ex-vivo production of interleukin (IL)-1ß, tumour necrosis factor-α (TNF-α) and IL-6 in whole blood samples was measured with and without stimulation by LPS. RESULTS: At baseline, plasma ACTH and cortisol levels were not different between patients with RA and HC. The unstimulated production of IL-6 was significantly higher in RA patients than in HC. After 2 weeks of treatment with naproxen, urinary cortisol excretion decreased significantly (p=0.03), and the area under the curve for plasma cortisol during the ITT was significantly lower (p=0.015). The LPS stimulated production of IL-1ß was significantly lower compared with baseline. After 6 months, basal plasma, salivary and urinary cortisol levels, and plasma cortisol and ACTH levels during the ITT, were all unchanged in comparison to the pre-treatment period. The unstimulated ex-vivo production of IL-1ß was significantly lower than before treatment. CONCLUSIONS: Our results suggest that the non-steroidal anti-inflammatory drug naproxen suppresses the HPA-axis in the first weeks of treatment. After 6 months, this suppressive effect is no longer present, suggesting the existence of adaptive mechanisms.


Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Metotrexato/uso terapéutico , Naproxeno/uso terapéutico , Sistema Hipófiso-Suprarrenal/efectos de los fármacos , Sulfasalazina/uso terapéutico , Hormona Adrenocorticotrópica/sangre , Artritis Reumatoide/sangre , Artritis Reumatoide/fisiopatología , Glucemia/análisis , Citocinas/sangre , Quimioterapia Combinada , Femenino , Humanos , Hidrocortisona/metabolismo , Sistema Hipotálamo-Hipofisario/fisiología , Insulina , Masculino , Sistema Hipófiso-Suprarrenal/fisiología
6.
Breast ; 18(6): 351-5, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19836952

RESUMEN

We analysed the outcomes of women with metastatic breast cancer (MBC) from three randomised phase III trials of aromatase inhibitors according to oestrogen receptor (ER) and progesterone receptor (PgR) status. Both receptors were analysed in 1010 of the 1870 women (54%), including 31 that were ER-/PgR-, which were excluded. Of the remaining 979, 726 (74%) were ER+/PgR+ but 253 were single hormone receptor positive (213 ER+/PgR-, 40 ER-/PgR+). Although there were no differences in clinical benefit or time to progression, the median overall survival of women with ER+/PgR+ tumours was significantly longer than those with single HR positive tumours (800 versus 600 days, p=0.01). In women with ER+ tumours, the median overall survival of those with tumours that were also PgR+ was significantly longer than those that were PgR- (800 versus 625 days, p=0.02). The PgR status is an important prognostic factor for survival in MBC.


Asunto(s)
Inhibidores de la Aromatasa/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/secundario , Femenino , Humanos , Pronóstico , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Análisis de Supervivencia
8.
J Endocrinol ; 193(3): 473-80, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17535884

RESUMEN

Gilthead sea bream (Sparus auratus L.) were fed a vitamin D-deficient diet for 22 weeks. Growth rate, whole body mineral pools and calcium balance were determined. Plasma parathyroid hormone-related protein (PTHrP) and calcitriol levels were assessed. Expression of mRNA for pthrp and pth1r was quantified in gills and hypophysis. Fish on vitamin D-deficient diet (D- fish) showed reduced growth and lower calcium turnover (calcium influx, efflux and accumulation rates decreased) and unaltered plasma calcium levels. Plasma calcitriol levels became undetectable, PTHrP levels decreased in the D- fish. In controls, a significant increase in plasma PTHrP level over time was seen, i.e. it increased with body mass. Relationships were found between plasma PTHrP and the whole body pools of calcium, phosphorus and magnesium, indicative of a role for PTHrP in bone development. Expression of pthrp and pth1r mRNA was down-regulated in the hypophysis of D-fish, whereas in gill tissue, pthrp and pth1r mRNA were up-regulated. We conclude that lower pthrp mRNA expression and plasma values in D- fish reflect lower turnover of PTHrP under conditions of hampered growth; up-regulation of pthrp mRNA in gills indicate compensatory paracrine activity of PTHrP during calcitriol deficiency to guarantee well-regulated branchial calcium uptake. This is the first report to document a relation between PTHrP and calcitriol in fish.


Asunto(s)
Calcio/metabolismo , Regulación de la Expresión Génica , Proteína Relacionada con la Hormona Paratiroidea/sangre , Dorada/metabolismo , Deficiencia de Vitamina D/metabolismo , Alimentación Animal , Animales , Calcitriol/sangre , Branquias/metabolismo , Proteína Relacionada con la Hormona Paratiroidea/genética , Hipófisis/metabolismo , ARN Mensajero/análisis , Receptor de Hormona Paratiroídea Tipo 1/genética , Receptor de Hormona Paratiroídea Tipo 1/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Dorada/crecimiento & desarrollo
9.
Eur J Clin Invest ; 36(10): 674-81, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16968462

RESUMEN

BACKGROUND: According to the 'haemodynamic hypothesis', increased tissue perfusion predisposes to microangiopathy in diabetic patients. We hypothesized that the typical haemodynamic changes underlying the increased tissue perfusion can be explained by a decreased sympathetic nerve activity caused by chronic hyperglycaemia. In this study we investigated sympathetic activity in patients with uncomplicated type 1 diabetes mellitus (DM). MATERIALS AND METHODS: In 15 DM patients (DM duration 6.3 +/- 3.8 year; HbA1c 7.9 +/- 1.3%) and 16 age- and sex-matched healthy volunteers (Control), sympathetic nervous system activity was measured at rest (baseline) and during sympathoneural stimulation (lower body negative pressure (LBNP)) by means of interstitial and plasma noradrenaline (NA) sampling and power spectral analysis. Muscle sympathetic nerve activity (MSNA) was measured before (baseline) and during a cold pressure test. Forearm blood flow was measured during forearm vascular alpha- and beta-adrenergic receptor blockade. RESULTS: At baseline, forearm vascular resistance (FVR), plasma NA concentrations, MSNA and heart rate variability were similar in both groups. LBNP-induced vasoconstriction was significantly attenuated in the DM group compared with the Control group (DeltaFVR: 12 +/- 4 vs. 19 +/- 3 arbitrary units, P < 0.05). The responses of plasma NA and heart rate variability did not differ. CONCLUSIONS: Baseline FVR and sympathetic nerve activity are normal in patients with uncomplicated type 1 diabetes. However, the forearm vasoconstrictor response to sympathetic stimulation is attenuated, which cannot be attributed to an impaired sympathetic responsiveness.


Asunto(s)
Diabetes Mellitus Tipo 1/fisiopatología , Antebrazo/irrigación sanguínea , Flujo Sanguíneo Regional/fisiología , Sistema Nervioso Simpático/fisiología , Vasoconstricción/efectos de los fármacos , Antagonistas Adrenérgicos/administración & dosificación , Adulto , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Presión Negativa de la Región Corporal Inferior , Masculino , Músculo Esquelético/irrigación sanguínea , Norepinefrina/análisis
10.
Oncologist ; 9(5): 489-96, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15477633

RESUMEN

PURPOSE: The letrozole study 025 is a large (n = 907), international, double-blind, randomized, phase III trial in postmenopausal women with advanced breast cancer. This subanalysis compares the efficacies of letrozole and tamoxifen as first-line therapy in postmenopausual women with advanced breast cancer according to site of metastatic lesions and Karnofsky Performance Status (KPS). MATERIALS AND METHODS: Nine hundred seven patients with advanced breast cancer were randomly assigned to once-daily oral letrozole (2.5 mg; Femara; Novartis Pharma AG; Basel, Switzerland) or tamoxifen (20 mg; Tamofen; Leiras OY; Turku, Finland). Time to progression (TTP) was estimated using the Kaplan-Meier product-limit method. Treatments were compared by Cox proportional hazards regression models. RESULTS: Letrozole treatment significantly prolonged TTP in all subsets of patients: those with nonvisceral metastases, those with visceral metastases without liver involvement, and those with liver metastases. The reduction in risk of progression ranged from 25%, for patients with nonvisceral metastases, to 36%, for patients with liver metastases. The distributions of baseline KPS scores for both treatment groups were similar (57% had KPS scores >/=90). Time to worsening of 20 points or more in KPS score was significantly longer with letrozole than with tamoxifen, but modest numbers of patients experienced such deterioration (letrozole, 20%, tamoxifen, 22%, in patients without visceral metastases; 23%-24% in patients with liver metastases; and letrozole, 14%, tamoxifen, 30%, in patients with visceral metastases without liver involvement). CONCLUSION: These data demonstrate the consistent superiority of letrozole over tamoxifen and support the use of letrozole as a new standard of endocrine therapy in postmenopausal women with advanced breast cancer.


Asunto(s)
Antineoplásicos Hormonales/uso terapéutico , Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Nitrilos/uso terapéutico , Tamoxifeno/uso terapéutico , Triazoles/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/farmacología , Antineoplásicos Hormonales/farmacología , Método Doble Ciego , Femenino , Humanos , Estado de Ejecución de Karnofsky , Letrozol , Persona de Mediana Edad , Metástasis de la Neoplasia , Nitrilos/farmacología , Posmenopausia , Tamoxifeno/farmacología , Resultado del Tratamiento , Triazoles/farmacología
11.
Oncologist ; 9(5): 497-506, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15477634

RESUMEN

PURPOSE: To compare the efficacy, in regard to time to progression (TTP) and objective response rate (ORR), of letrozole (Femara; Novartis Pharma AG; Basel Switzerland), an oral aromatase inhibitor, with that of tamoxifen (Tamofen; Leiras OY; Turku, Finland) as first-line therapy in younger (<70 years) and older (>/=70 years) postmenopausal women with advanced breast cancer. MATERIALS AND METHODS: Nine hundred seven patients with advanced breast cancer were randomly assigned to receive 2.5 mg letrozole (n = 453) or 20 mg tamoxifen (n = 454) once daily in a double-blind, multicenter, international trial. Among the prospectively planned analyses were analyses of TTP and ORR by age (<70 and >/=70 years). The results of these prospectively planned analyses are reported here. RESULTS: Letrozole was as effective in older postmenopausal women (>/=70 years of age) as it was in younger postmenopausal women (<70 years of age). The overall ORR in the older subgroup was significantly higher in patients treated with letrozole (38%) than in patients treated with tamoxifen (18%). In the younger subgroup of postmenopausal patients, the ORRs were not significantly different (letrozole, 26%; tamoxifen, 22%). TTP was significantly longer for letrozole than for tamoxifen in both age groups (younger: letrozole median TTP, 8.8 months; tamoxifen, 6.0 months; older: letrozole median TTP, 12.2 months; tamoxifen, 5.8 months). Although age was independently prognostic of TTP, there was no significant effect of age on ORR in the presence of other factors. CONCLUSION: The data show that letrozole, 2.5 mg once daily, is as effective in older, postmenopausal women as it is in younger postmenopausal women with advanced breast cancer. In addition, letrozole was more effective than tamoxifen in both younger and older patients.


Asunto(s)
Antineoplásicos Hormonales/farmacología , Antineoplásicos Hormonales/uso terapéutico , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Nitrilos/farmacología , Nitrilos/uso terapéutico , Tamoxifeno/farmacología , Tamoxifeno/uso terapéutico , Triazoles/farmacología , Triazoles/uso terapéutico , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Progresión de la Enfermedad , Método Doble Ciego , Femenino , Humanos , Letrozol , Persona de Mediana Edad , Posmenopausia , Pronóstico , Resultado del Tratamiento
13.
Eur J Cancer ; 39(16): 2318-27, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14556923

RESUMEN

It was previously shown that letrozole (Femara) was significantly more potent than anastrozole (Arimidex) in inhibiting aromatase activity in vitro and in inhibiting total body aromatisation in patients with breast cancer. The objective of this study was to compare letrozole (2.5 mg per day) and anastrozole (1 mg per day) as endocrine therapy in postmenopausal women with advanced breast cancer previously treated with an anti-oestrogen. This randomised, multicentre and multinational open-label phase IIIb/IV study enrolled 713 patients. Treatment was for advanced breast cancer that had progressed either during anti-oestrogen therapy or within 12 months of completing that therapy. Patients had tumours that were either positive for oestrogen and/or progesterone receptors (48%) or of unknown receptor status (52%). The primary efficacy endpoint was time to progression (TTP). Secondary endpoints included objective response, duration of response, rate and duration of overall clinical benefit (responses and long-term stable disease), time to treatment failure, and overall survival, as well as general safety. There was no difference between the treatment arms in TTP; median times were the same for both treatments. Letrozole was significantly superior to anastrozole in the overall response rate (ORR) (19.1% versus 12.3%, P=0.013), including in predefined subgroups (receptor status-unknown, and soft-tissue- and viscera-dominant site of disease). There were no significant differences between the treatment arms in the rate of clinical benefit, median duration of response, duration of clinical benefit, time to treatment failure or overall survival. Both agents were well tolerated and there were no significant differences in safety. These results support previous data documenting the greater aromatase-inhibiting activity of letrozole and indicate that advanced breast cancer is more responsive to letrozole than to anastrozole as second-line endocrine therapy.


Asunto(s)
Antineoplásicos Hormonales/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Inhibidores Enzimáticos/uso terapéutico , Nitrilos/uso terapéutico , Triazoles/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Anastrozol , Femenino , Humanos , Letrozol , Persona de Mediana Edad
14.
J Clin Oncol ; 21(10): 1967-72, 2003 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-12743150

RESUMEN

PURPOSE: To determine the effect of elevated serum HER-2/neu on the response of metastatic breast cancer patients to an aromatase inhibitor versus an antiestrogen. PATIENTS AND METHODS: Five hundred sixty-two estrogen receptor-positive metastatic breast cancer patients were randomized to first-line hormone therapy with either letrozole or tamoxifen. An automated enzyme-linked immunosorbent assay was used to detect serum HER-2/neu. RESULTS: For patients with normal serum HER-2/neu (70.5%), objective response rate (ORR; 39% in letrozole-treated patients v 26% in tamoxifen-treated patients; P =.008), clinical benefit (CB; 57% v 45%; P =.016), time to progression (TTP; median, 12.2 v 8.5 months; P =.0019), and time to treatment failure (TTF; median, 11.6 v 6.2 months; P =.0066) were significantly better in patients treated with letrozole. In the elevated HER-2/neu group (29.5%), there was no significant difference in ORR (17% in letrozole-treated patients v 13% in tamoxifen-treated patients; P =.45) or CB (33% v 26%; P =.31), but there was a strong trend in favor of a longer TTP with letrozole (median, 6.1 v 3.3 months; P =.0596) and a significantly longer TTF with letrozole (median, 6.0 v 3.2 months; P =.0418). Multivariate analysis revealed that elevated serum HER-2/neu was a negative predictor for ORR and TTP. CONCLUSION: Patients with normal serum HER-2/neu receiving letrozole demonstrated a significantly greater ORR and CB and longer TTP and TTF than patients receiving tamoxifen. Although in patients with elevated serum HER-2/neu there was no significant difference between letrozole and tamoxifen in ORR or CB, there was a strong trend favoring longer TTP and significantly longer TTF with letrozole.


Asunto(s)
Antineoplásicos/uso terapéutico , Inhibidores de la Aromatasa , Neoplasias de la Mama/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Neoplasias Hormono-Dependientes/tratamiento farmacológico , Nitrilos/uso terapéutico , Receptor ErbB-2/sangre , Triazoles/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/sangre , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Supervivencia sin Enfermedad , Método Doble Ciego , Ensayo de Inmunoadsorción Enzimática , Antagonistas de Estrógenos/uso terapéutico , Femenino , Humanos , Letrozol , Persona de Mediana Edad , Metástasis de la Neoplasia , Recurrencia Local de Neoplasia/sangre , Recurrencia Local de Neoplasia/mortalidad , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Neoplasias Hormono-Dependientes/sangre , Neoplasias Hormono-Dependientes/mortalidad , Neoplasias Hormono-Dependientes/patología , Suiza , Tamoxifeno/uso terapéutico , Resultado del Tratamiento , Estados Unidos
15.
J Hered ; 94(2): 111-4, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12721222

RESUMEN

DNA Surveillance is a Web-based application that assists in the identification of the species and population of unknown specimens by aligning user-submitted DNA sequences with a validated and curated data set of reference sequences. Phylogenetic analyses are performed and results are returned in tree and table format summarizing the evolutionary distances between the query and reference sequences. DNA Surveillance is implemented with mitochondrial DNA (mtDNA) control region sequences representing the majority of recognized cetacean species. Extensions of the system to include other gene loci and taxa are planned. The service, including instructions and sample data, is available at http://www.dna-surveillance.auckland.ac.nz.


Asunto(s)
ADN , Delfines/genética , Marsopas/genética , Ballenas/genética , Animales , Bases de Datos Genéticas , Delfines/clasificación , Marsopas/clasificación , Programas Informáticos , Ballenas/clasificación
16.
Ann Clin Biochem ; 40(Pt 1): 75-8, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12542914

RESUMEN

BACKGROUND: Statistical testing of assay linearity using replicate measurements made on binary mixtures of samples provides no information about the significance of any detected deviations from linearity, which may often be desirable. METHOD: Performance of additional statistical analysis of the assay data. RESULT: Objective measures for non-linearity and the minimum detectable deviation from linearity of the assay are obtained. CONCLUSION: A few additional calculations from the available data make it possible to assess whether or not an assay method needs improvement to achieve adequate performance within its intended application.


Asunto(s)
Bioquímica/métodos , Química Clínica/métodos , Cromatografía Líquida de Alta Presión/métodos , Electroquímica/métodos , Modelos Estadísticos , Reproducibilidad de los Resultados
17.
Ann Clin Biochem ; 40(Pt 1): 94-9, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12542917

RESUMEN

BACKGROUND: As recurrences after treatment for differentiated thyroid cancer can occur many years after thyroidectomy, periodic monitoring of serum thyroglobulin (Tg) levels is performed in these patients. However, autoantibodies that can interfere with Tg immunoassays occur in the blood of approximately 25% of these patients. Several earlier reports suggest that measuring Tg mRNA by reverse-transcriptase polymerase chain reaction (RT-PCR) could be of value, especially in patients with Tg autoantibodies. METHODS: Using an earlier described, real-time quantitative Taqman RT-PCR assay, Tg mRNA concentrations were assessed in peripheral blood taken from 58 patients treated for thyroid cancer and from two healthy controls. RESULTS: In all tested samples Tg mRNA could be found. No correlation between serum Tg protein and Tg mRNA could be found. Tg mRNA concentrations did not differ between serum Tg-negative and Tg-positive patients. No differences in the number of patients with high or low Tg/beta-actin ratios were found between the groups of patients without, (131)I uptake on whole-body scan, or patients with thyroid bed uptake, uptake elsewhere in the neck, or distant metastases with or without regional uptake (P = 0.871). CONCLUSIONS: We were not able to confirm earlier positive reports on the clinical value of Tg mRNA measurement for the monitoring of patients treated for thyroid cancer.


Asunto(s)
Química Clínica/métodos , Tiroglobulina/sangre , Neoplasias de la Tiroides/sangre , Adulto , Anciano , Anciano de 80 o más Años , Calibración , Femenino , Humanos , Masculino , Persona de Mediana Edad , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Neoplasias de la Tiroides/diagnóstico , Neoplasias de la Tiroides/genética
18.
Eur J Clin Invest ; 32(12): 874-81, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12534445

RESUMEN

BACKGROUND: Vascular tone is increased in primary hypertension, and glucocorticoids affect vascular tone. Local cortisol availability is modulated by activity of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD). As this activity may be decreased in patients with primary hypertension, vascular sensitivity to cortisol may be increased in these patients. We studied the acute effect of cortisol on forearm vascular resistance (FVR) by infusing cortisol directly into the brachial artery, both with and without inhibition of 11 beta-HSD, in normotensive and hypertensive subjects. DESIGN: Twenty normotensive volunteers and 20 patients with primary hypertension participated in the study. After a 10-min infusion of vehicle (glucose 5%), cortisol was infused into the brachial artery in three stepwise increasing doses (3.5, 10.5 and 35 microg per 100 mL of forearm volume), each for 10 min. Next, the participants received placebo or 500 mg glycyrrhetinic acid (GA) orally, and 150 min later the same infusion schedule was repeated. Forearm vascular resistance was measured during the last 5 min of the infused vehicle and of each dose. Arterial and forearm venous plasma samples for measurement of cortisol and cortisone were taken at the end of the infusions of glucose 5% and the highest cortisol dose. RESULTS: In both normotensive and hypertensive subjects, neither the infusion of cortisol nor the administration of GA changed FVR. Also 2 h after the cortisol infusion there remained no change in FVR in both the normotensive and hypertensive groups who received placebo. Following the infusion of the highest cortisol dose, total plasma cortisone levels in the venous plasma were decreased compared with levels in the arterial plasma (36 +/- 3 and 49 +/- 4 nmol L-1, respectively, P < 0.05). The protein-bound venous cortisone was 37.1 +/- 4.8 nmol L-1 during the vehicle compared with 23.9 +/- 3.7 nmol L-1 during the cortisol infusion (P < 0.01), whereas the free cortisone level was not altered by the cortisol infusion. CONCLUSIONS: In both normotensive and hypertensive subjects, high-dose cortisol infusion both with and without 11 beta-HSD inhibition did not change FVR either immediately or after 2 h. We could not demonstrate in vivo 11 beta-HSD activity in the forearm vascular tissues. When binding of cortisone to CBG is changed, e.g. during cortisol infusion, arterio-venous changes in cortisone cannot reliably be used to assess (alterations in) local 11 beta-HSD activity.


Asunto(s)
Arteria Braquial , Ácido Glicirretínico , Hidrocortisona/administración & dosificación , Hidroxiesteroide Deshidrogenasas/antagonistas & inhibidores , Hipertensión/fisiopatología , Resistencia Vascular/efectos de los fármacos , 11-beta-Hidroxiesteroide Deshidrogenasas , Estudios de Casos y Controles , Cortisona/sangre , Método Doble Ciego , Femenino , Humanos , Hidrocortisona/sangre , Hipertensión/sangre , Infusiones Intraarteriales , Masculino , Persona de Mediana Edad , Estadísticas no Paramétricas
19.
Ann Clin Biochem ; 38(Pt 6): 722-30, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11732660

RESUMEN

A method for the determination of metanephrine (MN; also known as metadrenaline), normetanephrine (NMN; also known as normetadrenaline) and 3-methoxytyramine (3-MT) in human urine using high-performance liquid chromatography followed by electrochemical detection (ECD) was validated primarily by comparing the results with those obtained by a gas chromatography mass spectrometry (GC-MS) reference method. Correlation coefficients of 0.93, 0.94 and 0.91 were obtained for MN, NMN and 3-MT, respectively, in a group of healthy controls consisting of 30 women and 30 men. A systematic difference was detected only for 3-MT (-16%). Further tests of accuracy (linearity and recovery) and precision demonstrated that the described method must be considered to be a reliable approach to assess urinary metanephrines in the diagnosis of phaeochromocytoma. At lower concentrations (MN, 248 nmol/L; NMN, 434 nmol/L; 3-MT, 402 nmol/L), within-assay coefficients of variation were close to 5% or less (5.3, 4.6 and 2.2%, respectively) and between-assay coefficients of variation were 8.9, 11.2 and 12.3%, respectively, for the same low levels. This raises the possibility that this method can also be applied to assess urinary free, unconjugated metanephrines. Sex differences were detected for MN and NMN excretion when expressed in nmol per 24h and nmol/mmol creatinine, respectively, by both ECD and GC-MS methods.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Dopamina/análogos & derivados , Metanefrina/orina , Normetanefrina/orina , Neoplasias de las Glándulas Suprarrenales/diagnóstico , Neoplasias de las Glándulas Suprarrenales/orina , Adulto , Anciano , Cromatografía Líquida de Alta Presión/estadística & datos numéricos , Dopamina/orina , Electroquímica , Femenino , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Masculino , Persona de Mediana Edad , Feocromocitoma/diagnóstico , Feocromocitoma/orina , Valores de Referencia , Sensibilidad y Especificidad , Caracteres Sexuales
20.
Proteomics ; 1(6): 756-62, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11677781

RESUMEN

Changes in glycosylation of glycoproteins and glycolipids is a common feature of cancer and may influence cancer cell behaviour, perhaps by enabling cell-cell interactions which favour metastasis or by allowing cancer cells to evade immuno-surveillance. Studies to identify glycosylation changes in human cancer have often used immunohistochemical techniques with lectins or antibodies and human tissue sections. Whilst some detailed biochemical studies have been performed there are few clinically relevant studies since the numbers of specimens evaluated are often very small. Using an immuno-histochemical approach, we have found that the lectin HPA from the albumen gland of Helix pomatia detects aggressive metastatic breast cancers. We have sought to identify the breast cancer associated oligosaccharides and the proteins to which they are attached via 2-DE for proteome analysis and HPLC separations for glycosylation mapping. Sixty-nine breast cancer specimens were studied. The HPA staining pattern, clinical treatment and follow-up data were known. Oligosaccharides that related to HPA staining were identified and found in elevated levels in metastatic breast cancer specimens. Human breast and colorectal cancer cells grown in vitro and in a clinically relevant animal model of metastasis also show increased levels of the oligosaccharides. We are now structurally characterising the oligosaccharides and aim to use them as diagnostic tools and targets for immuno-therapy of breast and other solid tumours.


Asunto(s)
Neoplasias de la Mama/metabolismo , Procesamiento Proteico-Postraduccional , Proteoma , Neoplasias de la Mama/patología , Glicosilación , Humanos
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