Enhanced discrimination between flavor stimuli: roles of salience modulation and inhibition.

Rats were given intermixed preexposure to the compound flavors AX and BX and to the compound CX in a separate block of trials (4 presentations of each compound). In Experiment 1, rats showed less generalization of conditioned aversion from AX to BX than from CX to BX, a perceptual learning effect. Experiment 2 showed that the formation of an excitatory association proceeded more readily between A and B than between C and B, suggesting that intermixed preexposure maintains the effective salience of A and B and does not establish inhibition between them, a process that would require prolonged preexposure.

The Espinet and the perceptual learning effects in flavour aversion conditioning: do they depend on a common inhibitory mechanism?

In three experiments rats were given short or long preexposure (4 or 10 sessions) to two compound flavours, AX and BX, according to an intermixed or a blocked schedule. Following preexposure, aversion conditioning trials were given with AX as the conditioned stimulus (CS). In Experiments 1 and 2, retardation and summation tests were then carried out to assess the inhibitory properties of B (an Espinet procedure).

Indirect immunofluorescence study on the cytoskeleton of normal (FG) and neoplastic (SGS/3A) cadmium treated fibroblasts.

Cadmium is a heavy metal dangerous for the environment and for the human health, with well shown carcinogenic potentiality. Many studies have related the professional exposure of the Cadmium with human pulmonary, prostatic and renal tumors, and it would be a role also in the tumors of the liver, of the hemopoietic system, of the bladder and of the stomach. The aim of the current study is to examine in normal and neoplastic fibroblasts culture cells the modifications induced by the Cadmium at cellular level, in particular on the cytoskeleton, responsible not only of the intracellular transport of vesicles and cell organules, but also of their positioning and of the cellular integrity.

Release of alpha-actin into serum after skeletal muscle damage.

Objective: The skeletal muscle protein alpha-actin was investigated in the serum of subjects with severe skeletal muscle damage to assess its utility as a reliable and predictive marker of muscle damage.

Methods: Serum samples were obtained from 33 healthy controls and 33 patients with severe skeletal muscle damage, defined by a total creatine kinase value of >500 IU/l (Rosalki method). Troponin I, troponin T, and myoglobin concentrations were determined by immunoassay and alpha-actin concentrations by Western blot and densitometry.

Non-viral and viral vectors for gene therapy.

Human gene therapy can be defined as the delivery of genetic material into a patient's cells with a therapeutic aim. The success or failure of gene therapy depends on the development and efficiency of the transfection of viral and non-viral vectors. Viral vectors typically offer higher transduction efficiency and long-term gene expression, but may be associated with toxicity, immunogenicity, restricted target cell specificity and high cost.

Modulation of the effective salience of a stimulus by direct and associative activation of its representation.

In 2 experiments, rats received exposure to presentations of a footshock preceded by a given cue. In the PRf (partial reinforcement) condition, this cue also occurred in the absence of the shock; in the CRf (continuous reinforcement) condition, it did not. Subsequent testing in which a new stimulus was used to signal the shock (Experiment 1) showed that the shock was more effective as a reinforcer for the PRf than for the CRf group.

Growth inhibition, G(1)-arrest, and apoptosis in MCF-7 human breast cancer cells by novel highly lipophilic 5-fluorouracil derivatives.

In this study we evaluate the antitumour activity, the cell cycle arrest and apoptotic properties of novel lipophilic benzene-fused seven-membered 5-fluorouracil (5-FU) analogs in comparison to 5-FU on MCF-7 human breast cancer cells. The lipophilicities of ESB-786B, ESB-252A and ESB-928A were predicted by using the CDR option of the PALLAS 2.0 program.

Mining mass spectra for diagnosis and biomarker discovery of cerebral accidents.

In this paper we try to identify potential biomarkers for early stroke diagnosis using surface-enhanced laser desorption/ionization mass spectrometry coupled with analysis tools from machine learning and data mining. Data consist of 42 specimen samples, i.e.

Dissociation between the Espinet and perceptual learning effects in flavour aversion conditioning.

In three experiments rats were given pre-exposure to two compound flavours, AX and BX, the two compounds being presented for some subjects on alternate trials (the intermixed schedule) and, for others, in separate blocks of trials (the blocked schedule). After aversion conditioning with A (in Experiments 1 and 2), the inhibitory properties of B were tested using both retardation (Experiment 1) and summation tests (Experiment 2). The results failed to support the proposal [Anim.

Contractile regulatory proteins tropomyosin and troponin-T as indicators of the modulatory role of retinoic acid.

Retinoic acid (RA), the active metabolite of vitamin A, plays a significant role in regulating cardiac form and function throughout the life of the organism. Both cardiac morphogenesis and myocardial differentiation are affected by alterations in RA homeostasis. In order to test the effect of all-trans RA and 13-cis RA on cardiomyocyte differentiation, we studied the level and the subcellular compartmentalization of alpha-tropomyosin and troponin-T proteins in cultures of chick embryo cardiomyocytes obtained from Hamburger and Hamilton's (HH) stage 22, 32 and 40 embryos.

Recovery effects after extinction in the Morris swimming pool navigation task.

In three experiments in which rats were used as subjects, we developed an extinction procedure using a Morris pool. The animals were trained to find a hidden platform located at a fixed position and were then given extinction trials in which the platform was removed from the pool. When training and extinction were carried out in the same context and time was allowed to elapse between extinction and test, spontaneous recovery of learning was observed.

Inhibition of growth and induction of apoptosis in human breast cancer by transfection of gef gene.

The gef gene has cell-killing functions in Escherichia coli. To evaluate the feasibility of using this gene as a new strategy for cancer therapy, we transfected it in MCF-7 cells derived from breast cancer (MCF-7TG). The gef gene was cloned in a pMAMneo vector under the control of a mouse mammary tumour virus promoter, inducible by dexamethasone (Dex), and was transfected with liposomes.

Transfection of MS-36 melanoma cells with gef gene inhibits proliferation and induces modulation of the cell cycle.

The gef gene, found in Escherichia coli DNA, encodes a small (50 amino acids) protein which is related to cell-killing functions. We used the MS-36 melanoma cell line as an experimental model to examine the usefulness of the gef gene as a new strategy for cancer therapy. We transfected MS-36 cells using the pMAMneo vector, and induced gef gene expression with dexamethasone.

Modulation of HLA class I expression in multidrug-resistant human rhabdomyosarcoma cells.

An abnormal HLA expression has been detected in some tumors including rhabdomyosarcoma (RMS). Classical cytotoxic treatment of these tumors, the most common childhood soft tissue malignancy, may induce multidrug resistance (MDR) associated with the expression of a 170-kDa membrane-associated glycoprotein (P-glycoprotein). In order to analyse the connection between modulation of HLA expression and the development of the MDR phenotype mediated by P-glycoprotein in RMS, we used three resistant RMS cell lines; two of these resistant cell lines (TE.

[Variations in the application of medical techniques in primary health care].

Objectives: To describe the application of medical techniques (ATM) in Spain and to analyze the relationship with diverse characteristics related to general practitioners and the center of primary health.

Design: Multicenter cross-sectional study.

Setting: Three hundred nineteen general practitioners working in primary care centers in the restructured public sector of the Autonomous Communities of Andalusia, Basque Country and Catalonia in Spain.

Reverse transcriptase-polymerase chain reaction detection of circulating tumor cells in patients with melanoma: correlation with clinical stage, tumor thickness and histological type.

The aim of this study was to evaluate the correlation between the detection of circulating melanoma cells and prognostic criteria for malignant melanoma such as clinical stage, tumor thickness and histological type of the primary tumor. Using a reverse transcriptase-polymerase chain reaction (RT-PCR) technique, melanoma cells were identified by detecting tyrosinase mRNA in peripheral blood from 58 patients with malignant melanoma classified according to the American Joint Committee on Cancer guidelines. The results of the RT-PCR assay for tyrosinase were related to two prognostic markers typically used to evaluate these tumors: clinical stage and thickness.

The effects of pre-exposure on escape from a Morris pool.

In two experiments rats were pre-exposed to the landmarks surrounding a Morris pool while they swam to a platform with a beacon attached to it. They were then required to escape from the pool by finding the platform, without the beacon, in a new position. When the platform remained in the same place for each pre-exposure session, but was moved from session to session, then subsequent escape from the pool was more rapid than when the landmarks were not visible during pre-exposure (Experiment 1).

Modulation of myogenic differentiation in a human rhabdomyosarcoma cell line by a new derivative of 5-fluorouracil (QF-3602).

The in vitro study of mechanisms involved in drug-induced maturation has made it possible to use differentiation-based therapy in clinical practice. The goal of this new therapy is the development of specific agents to induce cancer cells to stop proliferating and express characteristics of normal cells. Recently, by structural modifications of 5-fluorouracil (5-FU), we synthesized a new pyrimidine acyclonucleoside-like compound, 1-¿[3-(3-chloro-2-hydroxypropoxy)-1-methoxy]propyl¿-5-fluorouracil (QF-3602), which showed in rhabdomyosarcoma cells a low toxicity and time-dependent growth inhibition.

Development of chick cardiomyocytes: modulation of intermediate filaments by basic fibroblast and platelet-derived growth factors.

Recent studies suggest that peptide growth factors play a functional role in cardiac muscle. To test whether embryonic cardiac muscle is a target for regulation by basic fibroblast growth factor and platelet-derived growth factor, we analyzed the effects of these peptides on the expression of the intermediate filaments desmin and vimentin at the subcellular level during development. Sodium dodecyl sulfate-gel electrophoresis, immunoblotting and fluorescence-activated cell sorting analysis were used to study the effect of basic fibroblast growth factor and platelet-derived growth factor on cultures of chick cardiomyocytes during development.

Effects of varying the amount of preexposure to spatial cues on a subsequent navigation task.

In each of two experiments rats were preexposed to four compound landmarks (AX, BX, CX, and DX) one at a time; they were then trained to find a submerged platform located in a fixed position in a swimming pool using these same landmarks. When the preexposure was SHORT (4 sessions) it facilitated subsequent learning (a perceptual learning effect), whereas when rats were given a LONG preexposure phase (8 sessions) this facilitatory effect disappeared. EXTRA-LONG preexposure (16 sessions) reversed the facilitatory effect--that is to say, we observed retarded learning.

The influence of passive preexposure on escape from a Morris pool.

In 3 experiments rats were preexposed to the landmarks that surround a Morris pool by being placed on a submerged platform within the pool. They were then required to escape from the pool by swimming to the platform, which was in a location that had not been used during preexposure. Preexposure facilitated subsequent escape from the pool, provided that the platform was not moved during preexposure and the relative position of the landmarks to each other remained constant throughout preexposure.

Multidrug resistance phenotype in the RMS-GR human rhabdomyosarcoma cell line obtained after polychemotherapy.

Classical cytotoxic treatment of rhabdomyosarcoma (RMS), the most common soft tissue malignacy in children, is often accompanied by significant morbidity and poor response. Chemotherapy may induce multidrug resistance (MDR) associated with the expression of P-glycoprotein, a drug efflux pump which modifies the sensitivity of tumoral cells to drugs. To analyze MDR in RMS we used the RMS-GR cell line, obtained from an embryonal rhabdomyosarcoma treated in vivo with polychemotherapy.

Normal and anomalous pancreaticobiliary union in children and adolescents.

Background: The normal length of the pancreaticobiliary union (common channel) in the pediatric population is not known, nor is the frequency of anomalous pancreaticobiliary union and the extent to which it is associated with pancreaticobiliary disease.

Methods: ERCP was performed on 136 patients younger than 1 year (group 1) and 128 older than 1 year (group 2).

Results: In group 1 the average length of the common channel was 1.