Quantification of melanoma cell-specific MART-1 mRNA in peripheral blood by a calibrated competitive reverse transcription-PCR.

Background: Reverse transcription-PCR (RT-PCR) amplification of melanoma cell-specific mRNA can detect melanoma cells in the peripheral blood of patients with malignant melanoma. We present a method to quantify mRNA coding for the melanoma-specific melanoma antigen recognized by T cells #1 (MART-1) in RNA isolated from peripheral blood.

Methods: To establish a calibration curve, we measured the concentration of MART-1 mRNA in SK-MEL-28 melanoma cells grown in vitro by competitive RT-PCR.

Measurement of transcobalamin by ELISA.

Background: Transcobalamin is essential for the cellular internalization of cobalamin. Methods to quantify the unsaturated protein are available, but few attempts have been made to develop methods to quantify the sum of unsaturated and cobalamin saturated transcobalamin.

Methods: gamma-Globulins from two polyclonal rabbit antibodies against recombinant human transcobalamin were used as capture and detection antibodies, and recombinant human transcobalamin was used as calibrator in an ELISA design.

Quantitation of the mRNA expression of the epidermal growth factor system: selective induction of heparin-binding epidermal growth factor-like growth factor and amphiregulin expression by growth factor stimulation of prostate stromal cells.

The epidermal growth factor (EGF) system is a rapidly expanding system of growth factors involved in many aspects of normal and cancerous growth. We have developed a method for the quantitation of mRNA coding for all six growth factors activating the human EGF receptor (HER-1) and for the quantitation of mRNA for the receptors HER-1 and its preferred dimerization partner, HER-2. The method is based on the generation of specific RNA standards, which are amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) with the sample RNA and a set of calibrators.

Systemic treatment with epidermal growth factor causes organ growth concomitant with reduced circulating levels of IGF-I and IGFBP-3: time-dependent changes in female rats.

Systemic treatment with epidermal growth factor (EGF) in neonatal rats reduces circulating levels of insulin-like growth factor I (IGF-I) and causes somatic growth retardation. In this study, we investigated the effects of EGF treatment on the IGF system and on visceral organ growth and longitudinal growth in mature rats. We treated female Wistar rats for 0 (n = 16), 1 (n = 8), 2 (n = 8), 3 (n = 8), or 4 (n = 8) weeks with subcutaneous EGF (150 microg/kg/day).

Evaluation of novel assays in clinical chemistry: quantification of plasma total homocysteine.

Background: There is a need for systematic evaluation of methods before their release to the market. We addressed this problem in novel homocysteine assays as part of an European Demonstration Project involving six centers in four countries.

Methods: Two immunological methods for measurement of plasma total homocysteine (P-tHcy), the fluorescence polarization immunoassay (FPIA) and the enzyme immunoassay (EIA), were compared with two comparison methods, HPLC and gas chromatography-mass spectrometry (GC-MS).

Systemic treatment with epidermal growth factor but not insulin-like growth factor I decreases the involution of the prostate in castrated rats.

Epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) are strong inducers of proliferation to prostate cells cultured in serum-free medium. Accordingly we wanted to study the growth of the prostate gland in castrated rats after treatment with EGF, IGF-I and testosterone. Castrated Wistar rats were treated with growth factors (EGF 35 microg/rat per day; IGF-I 350 microg/rat per day) or testosterone (2 mg/rat per day) for 3 days either immediately after or 10 days after castration.

Renal content and output of epidermal growth factor in long-term adrenergic agonist-treated rats.

This study investigates the renal and urinary levels of epidermal growth factor (EGF) in rats under long-term treatment with alpha- or beta-adrenergic agonists. Urine samples were obtained on days 7, 14 and 21, and renal tissue samples on day 21. EGF was quantified by ELISA and tissue sections were used for immunohistochemistry and in situ hybridization.

The marker of cobalamin deficiency, plasma methylmalonic acid, correlates to plasma creatinine.

Objective: To examine the relationship between the two diagnostic tests, plasma methylmalonic acid and plasma cobalamins, and their association with plasma creatinine, age and sex.

Design: Cross-sectional study of simultaneous laboratory measurements.

Setting: County of Aarhus, Denmark.

Epidermal growth factor and insulin-like growth factor I upregulate the expression of the epidermal growth factor system in rat liver.

Background/aim: Both epidermal growth factor and insulin-like growth factor I play a role in connection with the liver. In the present study, the possible interaction of these two growth factor systems was studied by investigating the effect of epidermal growth factor or insulin-like growth factor I treatment on the expression of the epidermal growth factor receptor, and its activating ligands, transforming growth factor-alpha and epidermal growth factor.

Methods: Fifty-five male rats received no treatment, human recombinant epidermal growth factor or human recombinant insulin-like growth factor I for either 3 or 7 days.

Increased expression of heparin binding EGF (HB-EGF), amphiregulin, TGF alpha and epiregulin in androgen-independent prostate cancer cell lines.

Background: The proliferation of androgen-independent prostate cancer cell lines has previously been shown to be influenced by an autocrine loop of the epidermal growth factor (EGF) system. This observation has alerted us to study the expression of ligands and receptors from the EGF-system in prostate cell lines.

Methods: The expression of the EGF system was determined by quantitative RT-PCR and ELISA in the normal prostate epithelial cell line (PNT1A), in the androgen sensitive-(LNCaP), and the androgen-independent (DU145 and PC3) prostate cancer cell lines.

Conformational changes of transcobalamin induced by aquocobalamin binding. Mechanism of substitution of the cobalt-coordinated group in the bound ligand.

Binding of aquo-, cyano-, or azidocobalamin (Cbl.OH(2), Cbl.CN, and Cbl.

Physicians' use of plasma methylmalonic acid as a diagnostic tool.

Objectives: To investigate physicians' reasons for requesting plasma methylmalonic acid and their reactions to an increased concentration of plasma methylmalonic acid.

Design: Study of medical records.

Setting: Three somatic district hospitals in Denmark.

Epidermal growth factor and lung development in the offspring of the diabetic rat.

Fetuses of diabetic mothers who were exposed to excessive glucose show delayed maturation. Under these conditions, altered growth factor expression or signaling may have important regulatory influences. We examined the role of epidermal growth factor (EGF) in lung development and maternal diabetes in the rat.

Metabolism of oral trefoil factor 2 (TFF2) and the effect of oral and parenteral TFF2 on gastric and duodenal ulcer healing in the rat.

Background: Trefoil factors (TFFs) are peptides produced by mucus-secreting cells in the gastrointestinal tract. A functional association between these peptides and mucus, leading to stabilisation of the viscoelastic gel overlying the epithelia, has been suggested. Both oral and parenteral administration of the peptides increase the resistance of the gastric mucosa.

Sequence, S-S bridges, and spectra of bovine transcobalamin expressed in Pichia pastoris.

Transcobalamin (TC) -encoding cDNA was isolated from a bovine mammary gland cDNA library. Hybridization of the cloned bovine TC-cDNA to RNA samples from bovine tissues showed that the most intensive synthesis of a TC positive 1.9-kilobase mRNA occurred in kidney, lymphatic nodes, and liver.

Expression of transforming growth factor alpha and epidermal growth factor receptor in human bladder cancer.

We analysed the expression of epidermal growth factor receptor (EGFr) and transforming growth factor alpha (TGF-alpha) in human bladder tumours. Tumour biopsies were obtained from 54 patients with primary bladder cancer (18 stage T1 and 36 stage T2-4). The protein and mRNA expression of EGFr and TGF-alpha were quantified by ELISA and competitive RT-PCR, respectively.

Molecular dissection of the intrinsic factor-vitamin B12 receptor, cubilin, discloses regions important for membrane association and ligand binding.

Cubilin, the receptor for intrinsic factor-vitamin B12, is a novel type of high molecular weight receptor consisting of a 27 CUB (complement components C1r/C1s, Uegf, and bone morphogenic protein-1) domain cluster preceded by 8 epidermal growth factor repeats and a short N-terminal sequence. In addition to binding the vitamin B12-carrier complex, cubilin also binds receptor-associated protein. To delineate the structures for membrane association and ligand binding we established a panel of stable transfected Chinese hamster ovary cells expressing overlapping segments of rat cubilin.

Adsorption of EGF receptor ligands to test tubes--a factor with implications for studies on the potency of these peptides.

Studies on the relative potency of ligands for the epidermal growth factor receptor are usually performed with highly purified ligand specimens. However, adsorption of ligands to glass and plastic surfaces may affect the results by reducing the ligand concentration in an unpredictable way. The aim of this study was to examine the adsorption of four epidermal growth factor (EGF) receptor ligands, EGF, transforming growth factor alpha (TGF-alpha), heparin binding-EGF (HB-EGF) and betacellulin, to commonly used test tubes of polyethylene, polystyrene and glass, respectively.

Holotranscobalamin - a sensitive marker of cobalamin malabsorption.

Background: No simple and reliable method of identifying patients with cobalamin malabsorption is available at present. The measurement of plasma holotranscobalamin, i.e.

Distribution and metabolism of intravenously administered trefoil factor 2/porcine spasmolytic polypeptide in the rat.

Background: Trefoil peptides are secreted by mucus producing cells in the gastrointestinal tract and are supposed to be involved in oligomerisation processes of the mucin glycoproteins in the lumen. Endocrine functions have also been suggested.

Aims: To target possible binding sites for iodine-125 labelled porcine spasmolytic polypeptide (pSP) in an in vivo rat model.

Ureteral growth in animal models with increased renal excretion of urine.

The influence of increased functional load on the macroscopical and histological appearance of the ureter was investigated. Sixty rats were divided into five groups: (1) sucrose-fed rats with non-osmotic polyuria; (2) diabetic rats with osmotic polyuria; (3) uninephrectomized rats; (4) sham-operated control rats; and (5) control rats. The 24-hour urinary volume was measured on days 7, 14 and 21.