Particulate substrate retention in plug-flow and fully-mixed conditions during operation of aerobic granular sludge systems.

Particulate substrate (XB) is the major organic substrate fraction in most municipal wastewaters. However, the impact of XB on aerobic granular sludge (AGS) systems is not fully understood. This study evaluated the physical retention of XB in AGS sequencing batch reactor (SBR) during anaerobic plug-flow and then aerobic fully-mixed conditions. The influence of different sludge types and operational variables on the extent and mechanisms of XB retention in AGS SBR were evaluated. XB mass-balancing and magnetic resonance imaging (MRI) were applied. During the anaerobic plug-flow feeding, most XB was retained in the first few cm of the settled sludge bed within the interstitial voids, where XB settled and accumulated ultimately resulting in the formation of a filter-cake. Sedimentation and surface filtration were thus the dominant XB retention mechanisms during plug-flow conditions, indicating that contact and attachment of XB to the biomass was limited. XB retention was variable and influenced by the XB influent concentration, sludge bed composition and upflow feeding velocity (vww). XB retention increased with larger XB influent concentrations and lower vww, which demonstrated the importance of sedimentation on XB retention during plug-flow conditions. Hence, large fractions of influent XB likely re-suspended during aerobic fully-mixed conditions, where XB then preferentially and rapidly attached to the flocs. During fully-mixed conditions, increasing floc fractions, longer mixing times and larger XB concentrations increased XB retention. Elevated XB retention was observed after short mixing times < 60 min when flocs were present, and the contribution of flocs towards XB retention was even more pronounced for short mixing times < 5 min. Overall, our results suggest that flocs occupy an environmental niche that results from the availability of XB during aerobic fully-mixed conditions of AGS SBR. Therefore, a complete wash-out of flocs is not desirable in AGS systems treating municipal wastewater.

Metabolic fitness in relation to genetic variation and leukocyte DNA methylation.

Metabolic syndrome (MetS) is a highly prevalent condition causing increased risk of several life-threatening diseases. MetS has a pronounced hereditary basis but is also influenced by environmental factors, partly through epigenetic mechanisms. In this study, the five phenotypes underlying MetS were incorporated into a continuous score for metabolic fitness (MF), and associations with both genotypic variation and leukocyte DNA methylation were investigated. Baseline MF phenotypes (waist circumference, blood pressure, blood glucose, serum triglycerides, and high-density lipoproteins) of 710 healthy Flemish adults were measured. After a 10 yr period, follow-up measures were derived from 618 of these subjects. Genotyping was performed for 65 preselected MF-related genetic variants. Next, full genetic predisposition scores (GPSs) were calculated, combining genotype scores of multiple genetic variants. Additionally, stepwise GPSs were constructed, including only the most predictive genetic variants for the different MF phenotypes. For a subset of 68 middle-aged men, global and gene-specific DNA methylation was investigated, and a biological pathway analysis was performed. The full GPSs were predictive for some baseline MF phenotypes, but not for changes over time. Only a limited number of genetic variants were significantly predictive individually. On the contrary, global and gene-specific DNA methylation was associated with changes in the MF phenotypes rather than with the baseline measures, indicating that effects of DNA methylation on MF are somewhat delayed. Furthermore, several biological pathways were associated with the MF phenotypes through gene promoter methylation. For CETP, G6PC2, MC4R, and TFAP2B both a genetic and epigenetic relationship was found with MF.

Screening tools for evaluation of depression in Chronic Obstructive Pulmonary Disease (COPD). A systematic review.

Background: Anxiety and depression are common comorbid disorders in patients with chronic obstructive pulmonary disease (COPD), though estimates of their prevalence vary considerably. Depressive symptoms/depression are important comorbidities in COPD and an increasing interest is shown to these disorders. Depression may lead to reduced quality of life and increased morbidity and mortality. These statements underline the importance of implementing the use of screening instruments for depressive symptoms in a clinical setting. This systematic review evaluates four commonly used screening tools for depression in COPD. Furthermore we assess the prevalence of depression in COPD in the evaluated studies. Design: A literature search identified studies dealing with screening for depression in patients with COPD. We focused on the instruments: Beck Depression Inventory, Geriatric depression scale, Centre for Epidemiological Studies scale on Depression and Hospital and Anxiety Depression Scale. Results: Overall prevalence of depression was 30%. Demographic variations and severity of COPD influenced prevalence. The inter-prevalence of the four screening tools was consistent. We found a low variation between studies using the same tool. Few studies used control groups or compared the screening tool to a psychiatrist evaluation. Conclusions: This article calls for further investigation of the association between COPD and depressive symptoms. The subject is highly relevant for everyday life of patients with COPD and attention needs to be drawn to this issue in both an out- and in-patients.

pH measurements of FET-based (bio)chemical sensors using portable measurement system.

In this study we demonstrate the sensing capabilities of a portable multiplex measurement system for FET-based (bio)chemical sensors with an integrated microfluidic interface. We therefore conducted pH measurements with Silicon Nanoribbon FET-based Sensors using different measurement procedures that are suitable for various applications. We have shown multiplexed measurements in aqueous medium for three different modes that are mutually specialized in fast data acquisition (constant drain current), calibration-less sensing (constant gate voltage) and in providing full information content (sweeping mode). Our system therefore allows surface charge sensing for a wide range of applications and is easily adaptable for multiplexed sensing with novel FET-based (bio)chemical sensors.

[Mammography screening in Germany. Current results and future challenges]. / Mammographiescreening in Deutschland. Aktuelle Ergebnisse und zukünftige Herausforderungen.

The concept of mammography screening is based on the expectation that early diagnosis in a preclinical tumor stage enables less invasive treatment with a better prognosis than detection in advanced tumor stages. Mammography screening was implemented in European countries after results from large randomized controlled trials showed that regular screening led to a significant reduction in breast cancer mortality by 25-30 %. Recently, a major review of breast cancer screening services in Europe concluded that the benefits of screening clearly outweighed the disadvantages. In comparison to other European screening nations the German mammography screening program is relatively new. The challenge to prove the effectiveness by reduction in mortality still has to be solved. Continuous evaluation and optimization concerning the quality of structure, processes and results already confirm the high quality of the nationwide German screening services.

Mammography Screening - as of 2013.

Introduction: Since 2008 the German Mammography Screening Programme has been available throughout Germany to all women aged between 50 and 69. The programme strictly follows the European Guidelines. There are controversial discussions in the media as well as in the specialised press. Materials and Methods: Overview of the available data with regard to an evaluation of randomised studies and with regard to quality-assured screening programmes in accordance with EU Guidelines (including data from 18 screening countries). Results: Positive effects of screening: reduction in mortality, less invasive treatment. Negative effects: False-positive diagnoses and biopsy recommendations, so-called overdiagnoses, radiation dose. Limits of screening: Interval carcinomas, incomplete reduction in mortality. A mathematical synopsis of the latest publications from the European screening programmes with the diagnosis rates in Germany determined from > 4.6 million screening examinations produces the following: a total of 10 000 mammograms are created for 1000 women (P) taking part in the Mammography Screening Programme (each of whom undergoes 10 mammograms in 20 years). Overall, the risk of triggering breast cancer through a mammogram is very clearly below the annual natural risk of suffering from breast cancer. In the German screening, of these 1000 women, an average of 288 women are called back once in 20 years as a result of changes that are ultimately benign (< 3 % per cycle). Of these, 74 of the 288 women undergo a biopsy due to a benign change (false-positive biopsy recommendations, usually punch or vacuum biopsies). According to EUROSCREEN, 71 carcinomas develop among participants (56 are discovered in the screening, 15 in the interval), and 67 carcinomas among non-participants (N-P) (in some cases, several years later) during this period. The 4 additional diagnoses among the Ps are referred to as overdiagnoses, as they do not contribute to a reduction in mortality (these participants die beforehand from other causes of death). With regard to the carcinomas that concern the screening periods, 11 women out of 1000 die among the Ps; there are 19 deaths among the N-Ps (within the observation period plus follow-up period). Discussion: The false-positive rate is unavoidable, but is far lower with mammography screening than with other methods. Overdiagnoses are to be expected with any early detection. All calculations require assumptions and are therefore highly discrepant. They have very low evidence levels. The radiation dose should not be an argument against screening when applied correctly due to the very low risk and significant benefits. Interval carcinomas indicate the limits of a mammography screening programme. False-negatives only represent a subset of the interval carcinomas and are not to be equated with them. There is a very high evidence level for a significant reduction in mortality through mammography screening. For the first time, an independent expert commission has confirmed the results of the randomised studies and the statement of the WHO from 2002 and their further validity. Participants can expect a reduction in mortality of 30 %. Data from the current European screening programmes confirm a mortality reduction of 43 %, corresponding to 8/19 saved lives among 71 women with breast cancer or 1000 asymptomatic Ps. Many additional Ps benefit from less invasive treatment due to the early detection. Conclusions: As a result of the risk/benefit ratio, mammography screening should absolutely be recommended to asymptomatic women aged between 50-69. High importance is given to the provision of education for women by the treating gynaecologists as regards the opportunities for quality-assured early detection available to them in the healthcare system.

Training in the fasted state facilitates re-activation of eEF2 activity during recovery from endurance exercise.

Nutrition is an important co-factor in exercise-induced training adaptations in muscle. We compared the effect of 6 weeks endurance training (3 days/week, 1-2 h at 75% VO(2peak)) in either the fasted state (F; n = 10) or in the high carbohydrate state (CHO, n = 10), on Ca(2+)-dependent intramyocellular signalling in young male volunteers. Subjects in CHO received a carbohydrate-rich breakfast before each training session, as well as ingested carbohydrates during exercise. Before (pretest) and after (posttest) the training period, subjects performed a 2 h constant-load exercise bout (~70% of pretest VO(2peak)) while ingesting carbohydrates (1 g/kg h(-1)). A muscle biopsy was taken from m. vastus lateralis immediately before and after the test, and after 4 h of recovery. Compared with pretest, in the posttest basal eukaryotic elongation factor 2 (eEF2) phosphorylation was elevated in CHO (P < 0.05), but not in F. In the pretest, exercise increased the degree of eEF2 phosphorylation about twofold (P < 0.05), and values returned to baseline within the 4 h recovery period in each group. However, in the posttest dephosphorylation of eEF2 was negated after recovery in CHO, but not in F. Independent of the dietary condition training enhanced the basal phosphorylation status of Phospholamban at Thr(17), 5'-AMP-activated protein kinase α (AMPKα), and Acetyl CoA carboxylase ß (ACCß), and abolished the exercise-induced increase of AMPKα and ACCß (P < 0.05). In conclusion, training in the fasted state, compared with identical training with ample carbohydrate intake, facilitates post-exercise dephosphorylation of eEF2. This may contribute to rapid re-activation of muscle protein translation following endurance exercise.

Identification of spore allergens from the indoor mould Aspergillus versicolor.

BACKGROUND: Indoor mould growth and dampness are associated with respiratory health effects and allergies and several studies demonstrated that mainly Aspergillus versicolor and Penicillium expansum are responsible for indoor mould exposure. In contrast, commercialized test systems to diagnose allergic reactions to this mould species are not available. In this study, allergenic proteins from spores of the indoor relevant species A. versicolor and P. expansum should get detected and identified. METHODS: We used two-dimensional (2D)-gel electrophoresis of spore proteins and immunoblotting with sera from patients participating in an epidemiologic study about indoor exposure of moulds and their influence on the development of allergies (ESTERSPEGA). Sera were screened for IgE antibodies specific for proteins from A. versicolor, A. fumigatus and P. expansum in one-dimensional blots and in 2D immunoblots. From the 2D gels, the corresponding spots were picked and identified by mass spectrometry. RESULTS: More than 20 allergens from A. versicolor were identified; in particular, seven major allergens were selected, which were detected by more than 90% of the positive sera. The most abundant allergen was glyceraldehyde-3-phosphate dehydrogenase, followed by an unnamed protein, which displays a high homology to sobitol/xylose reductase. The other allergens were identified as catalase A, hypothetical protein AN6918.2, enolase, hypothetical protein AN0297.2 and a protein with homology to a fungal malate dehydrogenase. CONCLUSIONS: The results indicate an important role of spore proteins from A. versicolor for sensitization against indoor moulds and identification of the major allergens might enable species-specific diagnosis of allergic reactions.

Effect of training in the fasted state on metabolic responses during exercise with carbohydrate intake.

Skeletal muscle gene response to exercise depends on nutritional status during and after exercise, but it is unknown whether muscle adaptations to endurance training are affected by nutritional status during training sessions. Therefore, this study investigated the effect of an endurance training program (6 wk, 3 day/wk, 1-2 h, 75% of peak Vo(2)) in moderately active males. They trained in the fasted (F; n = 10) or carbohydrate-fed state (CHO; n = 10) while receiving a standardized diet [65 percent of total energy intake (En) from carbohydrates, 20%En fat, 15%En protein]. Before and after the training period, substrate use during a 2-h exercise bout was determined. During these experimental sessions, all subjects were in a fed condition and received extra carbohydrates (1 g.kg body wt(-1) .h(-1)). Peak Vo(2) (+7%), succinate dehydrogenase activity, GLUT4, and hexokinase II content were similarly increased between F and CHO. Fatty acid binding protein (FABPm) content increased significantly in F (P = 0.007). Intramyocellular triglyceride content (IMCL) remained unchanged in both groups. After training, pre-exercise glycogen content was higher in CHO (545 +/- 19 mmol/kg dry wt; P = 0.02), but not in F (434 +/- 32 mmol/kg dry wt; P = 0.23). For a given initial glycogen content, F blunted exercise-induced glycogen breakdown when compared with CHO (P = 0.04). Neither IMCL breakdown (P = 0.23) nor fat oxidation rates during exercise were altered by training. Thus short-term training elicits similar adaptations in peak Vo(2) whether carried out in the fasted or carbohydrate-fed state. Although there was a decrease in exercise-induced glycogen breakdown and an increase in proteins involved in fat handling after fasting training, fat oxidation during exercise with carbohydrate intake was not changed.

Evaluation of intramyocellular lipid breakdown during exercise by biochemical assay, NMR spectroscopy, and Oil Red O staining.

The study compared the net decline of intramyocellular lipids (IMCL) during exercise (n = 18) measured by biochemical assay (BIO) and Oil Red O (ORO) staining on biopsy samples from vastus lateralis muscle and by (1)H-MR spectroscopy (MRS) sampled in an 11 x 11 x 18-mm(3) voxel in the same muscle. IMCL was measured before and after a 2-h cycling bout ( approximately 75% V(.)(O(2) peak)). ORO and MRS measurements showed substantial IMCL use during exercise of 31 +/- 12 and 47 +/- 6% of preexercise IMCL content. In contrast, use of BIO for IMCL determination did not reveal an exercise-induced breakdown of IMCL (2 +/- 9%, P = 0.29) in young healthy males. Correlations between different measures of exercise-induced IMCL degradation were low. Coefficients were 0.48 for MRS vs. ORO (P = 0.07) and were even lower for BIO vs. MRS (r = 0.38, P = 0.13) or ORO (r = 0.08, P = 0.78). This study demonstrates that different methods to measure IMCL in human muscles can result in different conclusions with regard to exercise-induced IMCL changes. MRS has the advantage that it is noninvasive, however, not fiber type specific and hampered by an at least 30-min delay in measurements after exercise completion and may overestimate IMCL use. BIO is the only quantitative method but is subject to variation when biopsies have different fiber type composition. However, BIO yields lower IMCL breakdown compared with ORO and MRS. ORO has the major advantage that it is fiber type specific, and it therefore provides information that is not available with the other methods.

[Mammography screening]. / Mammographiescreening.

Exclusive biannual mammography screening for women ages 50-69 years reduces the mortality from breast cancer among participants by 35%. Compared with 50% of clinically detected cancers, only 20% of carcinomas detected in screening have nodal metastases, and up to 55% of screening carcinomas are in the T1 stage of "minimal cancer." In many European countries (including Sweden, Norway, the Netherlands, and Great Britain), mammography screening programmes have been established for more than 10 years. In Germany, the aim is to establish, by 2008, a nationwide organised programme on the basis of the European Guidelines for Quality Assurance. This goal requires 80-100 mammography screening units. The first screening units went into use in 2005. Women between 50 and 69 years are invited to participate in 2-year intervals.

Fiber type-specific muscle glycogen sparing due to carbohydrate intake before and during exercise.

The effect of carbohydrate intake before and during exercise on muscle glycogen content was investigated. According to a randomized crossover study design, eight young healthy volunteers (n = 8) participated in two experimental sessions with an interval of 3 wk. In each session subjects performed 2 h of constant-load bicycle exercise ( approximately 75% maximal oxygen uptake). On one occasion (CHO), they received carbohydrates before ( approximately 150 g) and during (1 g.kg body weight(-1).h(-1)) exercise. On the other occasion they exercised after an overnight fast (F). Fiber type-specific relative glycogen content was determined by periodic acid Schiff staining combined with immunofluorescence in needle biopsies from the vastus lateralis muscle before and immediately after exercise. Preexercise glycogen content was higher in type IIa fibers [9.1 +/- 1 x 10(-2) optical density (OD)/microm(2)] than in type I fibers (8.0 +/- 1 x 10(-2) OD/microm(2); P < 0.0001). Type IIa fiber glycogen content decreased during F from 9.6 +/- 1 x 10(-2) OD/microm(2) to 4.5 +/- 1 x 10(-2) OD/microm(2) (P = 0.001), but it did not significantly change during CHO (P = 0.29). Conversely, in type I fibers during CHO and F the exercise bout decreased glycogen content to the same degree. We conclude that the combination of carbohydrate intake both before and during moderate- to high-intensity endurance exercise results in glycogen sparing in type IIa muscle fibers.

Attitudes of patients, healthcare professionals and ethicists towards embryonic stem cell research and donation of gametes and embryos in Germany.

Due to the Embryo Protection Act, creation of supernumerary embryos, as well as egg and embryo donation, is prohibited in Germany. Human stem cell research is regulated through the Act on stem cells that came into force in 2002. A cross-sectional survey of 101 IVF couples (n=202) in two fertility centres, and representative samples of healthcare professionals and ethicists (n=879), was carried out, and their attitudes towards embryonic stem cell research and donation of gametes and embryos compared. A clear majority of IVF couples favoured legalization of egg and embryo donation and embryonic stem cell research for various purposes. The willingness of couples to donate was related to purpose and to other independent influences. The majority of physicians voted for legalization of embryonic stem cell production from surplus embryos. Most human geneticists and obstetricians approved egg, but not embryo, donation to other couples. Ethicists and midwives were opposed to every kind of donation and research on surplus embryos. The IVF couples surveyed have positive attitudes towards donation and research using surplus embryos, whereas the healthcare professionals and ethicists are predominantly sceptical about most research activities destroying human embryos. This difference should be considered carefully in legal and ethical discussions on reprogenetics.

Activation of the dioxin/aryl hydrocarbon receptor (AhR) modulates cell plasticity through a JNK-dependent mechanism.

Environmental chemicals such as dioxin adversely affect immune, neurological and reproductive functions and have been implicated in cancer development. However, the mechanisms responsible for dioxin toxicity are still poorly understood. Here, we show that dioxin and related pollutants trigger a marked morphological change in epithelial cells that remodel their cytoskeleton to increase interaction with extra cellular matrix while loosening cell-cell contacts. Furthermore, dioxin-treated cells show increased motility. These dioxin-mediated effects are mimicked by constitutive expression and activation of the intracellular dioxin receptor (aryl hydrocarbon receptor (AhR)). They correlate with activation of the Jun NH2-terminal kinase (JNK) and are reverted by treatment with a JNK inhibitor. Dioxin-induced effects occur 48 h post-treatment initiation, a time scale, which argues for a genomic effect of the AhR, linked to induction of target genes. This novel Ahr action on cell plasticity points to a role in cancer progression.

Rationale for a diagnostic chain in gestational breast tumor diagnosis.

Due to the physiological tissue alterations of the breast during pregnancy and lactation the diagnosis of a breast tumor by palpation, imaging and fine-needle biopsy is difficult and often unreliable. The purpose of our study was to review the value of imaging (mammography and ultrasonography) and biopsy techniques in order to work out a reliable protocol for evaluating gestational tumors. We performed a retrospective analysis of 25 patients with clinical diagnosis of gestational breast tumors during a 4-year period from 1995 to 1999. Specimens were obtained by core biopsy for histological examination. Invasive breast cancer was diagnosed in five patients, malignant lymphoma of the skin in one patient. The tumors in the remaining 19 patients proved benign. The overall accuracy was 0.91 for conventional mammography, 0.76 for conventional and panoramic ultrasound and 0.48 for color-coded sonography. Mammography as the most reliable imaging method should be used to evaluate all patients in whom ultrasonographic findings are suspicious for tumor. Radiation phobia should not prevent the performance of mammography under these circumstances. Nevertheless, all pre-operative methods of diagnosing gestational breast tumors other than core biopsy are unreliable.

[Origin and significance of leptin and neuropeptide Y (NPY) in amniotic fluid between the 14th and 18th weeks of gestation]. / Herkunft und Bedeutung von Leptin und Neuropeptid Y (NPY) im Fruchtwasser zwischen der 14. - 18. Schwangerschaftswoche.

INTRODUCTION: Leptin and neuropeptide Y (NPY) play important roles in the regulation of food intake, energy expenditure, hematopoesis and reproduction. The biological functions of leptin and NPY in fetal development, and their regulation during pregnancy by fetal and maternal factors remain poorly understood. PATIENTS AND METHODS: From 55 women undergoing diagnostic amniocentesis between the 14th and 18th weeks of gestation samples of amniotic fluid were collected. In accord with the circadian rhythm of leptin secretion all amniocenteses were performed between 8.00 and 12.00 a. m. The concentrations of leptin and NPY in amniotic fluid were analysed using commercially available RIA's. RESULTS: The amniotic fluid samples of 32 male and 23 female fetuses were determined and demonstrated no gender-dependent differences in leptin and NPY levels. No correlation was found between leptin/NPY and the maternal body mass index. NPY concentrations are lower in advanced gestational age pregnancies. Leptin levels revealed no differences with respect to gestational age. CONCLUSION: Leptin and NPY levels were independent of fetal gender and maternal BMI. This provides clues for alternative regulatory mechanisms in leptin and NPY secretion. Compared to the data of adults, our findings show high leptin concentrations in the amniotic fluid in the presence of only minor amounts of white adipose tissues which might include the placenta. Our data including the observation of lower levels of NPY in more advanced gestational age support the idea of specific factors regulating leptin and NPY secretion into the amniotic fluid.

[Interventional methods in diagnostics of the breast -- a new vacuum biopsy system for the breast in routine clinical practice]. / Interventionelle Methoden in der Mammadiagnostik -- Ein neues Mamma-Vakuumbiopsiesystem im täglichen klinischen Einsatz.

AIM: To evaluate the diagnostic potential of the new vacuum-assisted method VacuFlash (VF) in clinical routine of breast diagnostics. METHOD: From april 2002 to march 2003, the new sonographically guided vacuum-assisted system VacuFlash was used in 75 patients with a BI-RADS 5 lesion (analogue). The patients were aged between 31-75 yrs (median: 51 yrs), the size of the lesions measured 8-33 mm (median: 14 mm). 5 specimens were taken from each lesion. RESULTS: In 69 of the 75 lesions (92 %, respectively), malignancy was confirmed. In 8 lesions (8 %, resp.), we found a benign histology, confirmed by consecutive surgery. CONCLUSION: The new vacuum-assisted device VacuFlash is a technically perfected and applicable diagnostic method. Especially in the view of the cost it has to be compared with high-speed core cut biopsy, the hand-held Mammotome system and open surgical biopsy. High-speed core cut biopsy seems to be the standard procedure in diagnostic percutaneous breast intervention to clarify sonographically detected breast lesions.

[Mammographic breast density and breast cancer risk during HRT]. / Drüsenkörperdichte und Mammakarzinomrisiko unter HRT.

Higher breast density leads to a higher risk of breast-cancer coming along with a reduced sensitivity of mammography, the most important method for early diagnosis of breast cancer. HRT leads to an increase in breast density in up to (1/3) of treated women. Combined regimes of estrogen-progestin show a stronger influence than estrogen only. Changes of breast density appear almost entirely within the first year of administration and seem to be reversible after suspension of treatment within a few weeks. A possible solution of the dilemma is to perform mammography in asymptomatic premenopausal women during the first half of the menstrual cycle. In women with increased breast density using HRT it is recommended to modify the combination of hormones, change the application mode, or suspend HRT for a short period of 3 weeks prior to mammography. In symptomatic women with dense breasts, additive breast ultrasound is strongly recommended to reduce the otherwise high rate of missed breast cancers.

[Ultrasound examination of the breast with 7.5 MHz and 13 MHz-transducers: scope for improving diagnostic accuracy in complementary breast diagnostics?]. / Mamma-Sonographie mit 7.5 MHz versus 13 MHz: Ist eine Verbesserung der diagnostischen Sicherheit im Rahmen der komplementären Mammadiagnostik möglich?

AIM: Complementary diagnostic methods in early diagnosis of breast cancer are used to increase diagnostic accuracy and minimize unnecessary invasive diagnostic procedures. Aim of the following prospective, open multicenter clinical study was to define the value of high-frequency breast ultrasound with 13 MHZ transducers compared to standard breast ultrasound with 7.5 MHz. METHOD: Data of 810 female patients, aged 45 to 60 years, with 819 suspicious breast lesions evaluated by four participating centres between October 1996 and December 1997. Standardised breast ultrasound was performed uniformly using a AU4 IDEA diagnostic ultrasound system by Esaote-Biomedica in addition to a standardised procedure of clinical examination and standard-2view-mammography. Analysis of all aquired data and the correlating histopathological findings was done by means of descriptive statistics on the basis of an access datafile (Version 2.0). RESULTS: The histopathological evaluation showed 435 benign and 384 malignant findings. Overall sensitivity and specificity of the clinical examination were 71.1 % and 88.9 % and for mammography 84.7 % and 76.5 %, respectively. Standard ultrasound with 7,5 MHz reached a sensitivity of 82,6 % and a specificity of 80.8 % high-frequency ultrasound with 13 MHz came to 87.2 % and 78.4 %, respectively. Regarding tumour size, mammography gave the highest sensitivity in detection of pre-invasive cancers (DCIS). High-frequency breast ultrasound (13 MHz) proved to have a higher diagnostic accuracy compared to standard breast ultrasound (7,5 MHz) regardless of tumour size. Sensitivity was especially improved in case of small invasive tumours (pT1a) with 78 % versus 56 %, respectively. CONCLUSIONS: We conclude that high-frequency ultrasound is a valueable additive tool especially in the diagnosis of small tumours, improving diagnostic safety and reducing unnecessary invasive diagnostic procedures.