Breast cancer screening: first round in the population-based program in Valencia, Spain. Collaborative Group of Readers of the Breast Cancer Screening Program of the Valencia Community

PURPOSE: To analyze the results of round 1 of the population-based Valencia Breast Cancer Screening Program. MATERIALS AND METHODS: In this program, 78,224 (72.98%) of the 107,178 women invited (aged 45-65 years) underwent screening. Complementary views were obtained in 5,771 women (7.38%). Among the total population studied, 3,502 (4.48%) underwent short-term mammographic follow-up studies; 3,898 (4.98%) underwent additional studies and treatment at hospitals. Five hundred eighty-seven women (0.75%) underwent biopsy. RESULTS: Cancer was detected in 334 patients (4.27 cancers per 1,000 women [3.24 per 1,000 women aged 45-49 years, 6.30 per 1,000 women aged 60-65 years]; six patients with lobular carcinoma in situ excluded). The estimated sensitivity was 89%; specificity, 99%. The positive predictive value of mammography was 8.56%; of mammography with additional examinations, 26.82%; and of biopsy, 56.89%. Forty-one patients (12.28%) had ductal carcinoma in situ; 284 (85.03%) had infiltrating carcinoma. In 73 (25.70%) of the 284 patients, infiltrating carcinomas were smaller than 1 cm. Two hundred twenty-five patients (76.27%) had no lymph node involvement. One hundred seventy-nine (61.09%) had stage 0 or 1 cancer. CONCLUSION: Results are consistent with other published results; differences are due to methods and patient population characteristics.     

Optical-sectioning improvement in two-color excitation scanning microscopy

We present a new beam-shaping technique for two-color excitation fluorescence microscopy. We show that by simply inserting a properly designed shaded-ring filter in the illumination beam of smaller wavelength, it is possible to improve the effective optical sectioning capacity of such microscopes by 23%. Such an improvement is obtained at the expense of only a very small increasing of the overall energy in the point-spread-function sidelobes. The performance of this technique is illustrated by a numerical imaging simulation.     

Fast Screening Method to Determine Hop’s Phytoestrogens in Beer

A novel, fast, and simple method to determine three phytoestrogens [xanthohumol (XN), isoxanthohumol (IXN), and 8-prenylnaringenin (8PN)] in beer samples by high-performance liquid chromatography with diode-array detection has been developed. The selected method involves purification by solid phase extraction and separation achieved on a C₁₈ column by using a gradient elution program. This consists of a mixture of acetonitrile, water, and methanol (all of them with 1% of acetic acid) at a flow ratio of 1 mL/min. The detection wavelengths were set at 370 nm for XN and 280 nm for IXN and 8PN. Average analyte recoveries were higher than 75% with relative standard deviations lower than 5%. The detection limits were between 0.01 and 0.08 mg/L, and the quantitation limits were between 0.02 and 0.15 mg/L. The method has been validated and applied to the analysis of several types of commercial beers obtained from local markets, where results showed the presence of IXN and 8PN in most of the samples and the absence of XN. Thus, the presented method gives to brewing chemists a validated, reliable, fast, and affordable analytical tool to identify and quantify the three most important hop’s prenylflavonoids in beer.     

Effect of the enucleation procedure on the reprogramming potential and developmental capacity of mouse cloned embryos treated with valproic acid

Mouse recipient cytoplasts for somatic cell nuclear transfer (SCNT) are routinely prepared by mechanical enucleation (ME), an invasive procedure that requires expensive equipment and considerable micromanipulation skills. Alternatively, oocytes can be enucleated using chemically assisted (AE) or chemically induced (IE) enucleation methods that are technically simple. In this study, we compared the reprogramming potential and developmental capacity of cloned embryos generated by ME, AE, and IE procedures and treated with the histone deacetylase inhibitor valproic acid. A rapid and almost complete deacetylation of histone H3 lysine 14 in the somatic nucleus followed by an equally rapid and complete re-acetylation after activation was observed after the injection of a cumulus cell nucleus into ME and AE cytoplasts. In contrast, histone deacetylation occurred at a much lower level in IE cytoplasts. Despite these differences, the cloned embryos generated from the three types of cytoplasts developed into blastocysts of equivalent total and inner cell mass mean cell numbers, and the rates of blastocyst formation and embryonic stem cell derivation were similar among the three groups. The cloned embryos produced from ME and AE cytoplasts showed an equivalent rate of full-term development, but no offspring could be obtained from the IE group, suggesting a lower reprogramming capacity of IE cytoplasts. Our results demonstrate the usefulness of AE in mouse SCNT procedures, as an alternative to ME. AE can facilitate oocyte enucleation and avoid the need for expensive microscope optics, or for potentially damaging Hoechst staining and u.v. irradiation, normally required in ME procedures.     

Modelling relations between instrumental and sensory measurements in factorial experiments

In connection with the sensory evaluation of foods, chemical or physical measurements of the relevant sensory properties are often sought. The data available for testing whether one particular instrumental measurement is linearly related to a sensory variable usually arise from a factorial experiment rather than from some random sub-population. Thus, to calibrate the two variables properly and to test whether a linear relationship is compatible with the data, we need a statistical model that reflects the design. The ultrastructural model suggested by Dolby (Biometrika 63, 39–50, 1976) is one such model. Furthermore, this model allows for random variation in both of the variables considered. In this paper it is shown how testing and estimation may be carried out using this model, although the methods suggested are not optimal. Finally, it is argued that the use of factorial designs in this connection is sensible, or even necessary, despite the complications that it leads to in terms of statistical modelling and analysis.     

Coexpression of mRNA for the full-length neurotrophin receptor trk-C and trk-A in favourable neuroblastoma

Neuroblastoma, a childhood tumour of the sympathetic nervous system, may sometimes regress spontaneously in infants, or progress to a poor clinical outcome despite intensive therapy. Neuroblastomas express neurotrophin receptors and high levels of mRNA for trk-A correlates with favourable outcome, whereas trk-B mRNA is expressed by more unfavourable tumours. Using a sensitive RNase protection assay, mRNA expression for the neurotrophin receptor trk-C was investigated in 50 tumour samples from 45 children at different stages including metastatic and relapsing tumour tissue, out of which 22 were also investigated for trk-A mRNA. Thirty-seven of 43 primary tumours (86%) showed trk-C mRNA with more than 300-fold difference between the highest and the lowest values. A higher trk-C index (trk-C mRNA/GAPDH mRNA) was associated with favourable features such as younger age (P = 0.009-0.003), favourable tumour stage (1, 2 or 4S; P < 0.001) and favourable prognosis (P = 0.044). Better survival probability was shown in children with intermediate or high trk-C index compared with patients with low or undetectable levels (P = 0.031). All localised tumours co-expressed mRNA for trk-A and trk-C receptors. RT-PCR analysis detected mRNA encoding the cytoplasmic trk-C tyrosine kinase region only in favourable neuroblastomas. We conclude that favourable neuroblastoma may express the full-length trk-C receptor while unfavourable tumours, especially those with MYCN amplification, seem to either express no trk-C or truncated trk-C receptors with unknown biological function. Trk-C and possibly its preferred ligand NT-3 may be involved in the biology of favourable neuroblastomas showing apoptosis or differentiation.     

Parameters Influencing the Photocatalytic Activity of Suspension-Sprayed TiO2 Coatings

Photocatalytic properties of titania have been studied very intensively for a variety of applications, including air and water purification. In order to clarify the influence of the phase composition and other parameters, thermal spraying with suspensions was applied to produce photocatalytically active titania coatings starting from two commercially available anatase and rutile submicron powders. Aqueous suspensions containing 40% solids by weight were sprayed with an HVOF process using ethylene as the fuel gas. The spray parameters were chosen in order to produce mechanically stable coatings and to preserve a high content of the initial crystalline phases of the powders. The coating microstructures, phase compositions, and surface properties were characterized. The photocatalytic performance was evaluated by degradation of the pink dye Rhodamine B (RB) using two techniques: degradation of an aqueous solution of RB and discoloration of impregnated RB. All the coatings exhibited photocatalytic activity to varying degrees, depending on the phase composition as well as other factors, namely, the coating microstructure, surface morphology, surface hydroxylation, light absorption, and interaction with the pollutant.