Ultrasound velocity and attenuation of porcine soft tissues with respect to structure and composition: I. Muscle

Ultrasound velocity and attenuation of soft tissues have been widely investigated. However, few studies completely covered considerable variations of both, structure and composition. The aim of this study was to collect acoustic reference data of porcine Longissimus muscle and associate them with compositional traits. In addition, measurements were conducted on fresh, formalin fixed, and frozen-thawed samples to evaluate the effect of processing on ultrasound parameters and comparisons with earlier investigations. Measurement conditions (temperature and fibre orientation) were realised close to hanging carcasses conditions. Sound velocity ranged from 1617 ± 6 to 1622 ± 5 ms(-1), while attenuation mostly ranged from 1.0 ± 0.3 to 1.2 ± 0.3 dB MHz(-1)cm(-1). Only formalin fixed samples showed significantly higher attenuation (2.2 ± 0.6 dB MHz(-1)cm(-1)). Highest correlations have been observed between intramuscular fat and attenuation (up to r = .7). The obtained results are anticipated to improve ultrasound based estimation of the intramuscular fat of pig muscle on intact carcasses.     

Hard implant coatings with antimicrobial properties

Infection of orthopaedic implants often leads to inflammation immediately after surgery and increases patient morbidity due to repetitive operations. Silver ions have been shown to combine good biocompatibility with a low risk of inducing bacterial resistance. In this study a physical vapour deposition system using both arc deposition and magnetron sputtering has been utilized to produce silver ion doped TiN coatings on Ti substrates. This biphasic system combines the advantages of silver induced bactericidity with the good mechanical properties of TiN. Crystallographic analysis by X-ray diffraction showed that silver was deposited as well in its elementary form as it was incorporated into the crystal lattice of TiN, which resulted in increasing hardness of the TiN-coatings. Elution experiments revealed a continuous release of Ag ions in phosphate buffered saline. The coatings showed significant inhibitory effects on the growth of Staphylococcus epidermidis and Staphylococcus aureus and practically no cell-toxicity in cytocompatibility tests.     

Non-destructive estimation of the intramuscular fat content of the longissimus muscle of pigs by means of spectral analysis of ultrasound echo signals

The eating quality of porcine meat is supposed to increase with increasing intramuscular fat content (IMF). The aim of this study was to investigate the use of acoustic parameters obtained by spectral analysis of ultrasound echo signals to non-destructively predict intramuscular fat content of porcine longissimus muscle. Ultrasound is regarded as a promising non-destructive technique to characterize tissue. Ultrasound data acquisition was performed at slaughter with a clinical B-mode device equipped with a 3.5 MHz center-frequency transducer on 115 warm carcasses about 45 min postmortem. Acoustic parameters quantifying attenuation, backscattering and cepstral structure were calculated off-line from the recorded primary raw ultrasound echo signals. Their relationship to IMF content was investigated. IMF level significantly influenced powerspectrum amplitudes and backscatter parameters. With partial least-squares regression (PLS), the IMF content could be predicted with root mean standard error of prediction RMSEP of 0.36% IMF. The ultrasound parameters were able to correctly classify nearly 80% of the carcasses into HIGH and LOW level class, respectively. Results indicate the potential use of ultrasound spectral analysis for non-destructive evaluation (NDE) of pig carcasses in order to estimate the IMF content.     

Microbiological and mycotoxicological analyses of processed cereal-based complementary foods for infants and young children from the German market

This study investigated several food safety criteria in 38 different commercial products of processed cereal-based foods (PCF) from the German market. Microbiological assessment, followed by 16S RNA gene sequencing of suspect colonies, included aerobic mesophilic bacteria, moulds, Enterobacteriaceae, Cronobacter spp., and presumptive Bacillus cereus. Mycotoxin analyses were performed by enzyme immunoassays for deoxynivalenol (DON), zearalenone (ZEN), T-2/HT-2 toxins (T-2/HT-2; oat containing products only), ergot alkaloids (EA), and alternariol (AOH). No violative result above existing European Union regulations or international guidelines was obtained. Most samples had very low aerobic mesophilic cell counts (<2.0 × 10¹ CFU/g), the maximum was 9.6 × 10² CFU/g. A few samples contained low numbers of opportunistic pathogens, most notably Cronobacter sakazakii, Acinetobacter spp., Pantoea spp., and enterotoxigenic Bacillus wiedmannii. Levels of mycotoxin contamination were very low, well below European Union maximum limits. DON was found in 10 samples, at levels of 9–35 µg/kg. T-2/HT-2 were found in all 15 oat-based products (1–8 µg/kg). All samples were negative for ZEN and EA. A high number (n = 25) of samples yielded weakly positive results for the nonregulated AOH (0.4–2 µg/kg), but just three samples exceeded a level of 1 µg/kg. No relationship between cereal composition and analytical findings for microbiological parameters and mycotoxins could be found. As long as PCF meals are freshly prepared and consumed immediately after preparation, the risk from sporadically occurring opportunistic bacteria appears to be minimal.     

Studies on the immune status of patients with operated and irradiated cervical and breast cancer. III. Comparative investigation of the immune status of patients with breast cancer treated by operation and irradiation and of patients with cervical cancer treated either by operation or irradiation (author's transl)

The immunological reactivity of 19 operated cases of breast cancer (14 T1 2, 5T3) was investigated before and at 3-weekly intervals up to 12 weeks after radiotherapy by means of a large panel of techniques. The results were compared with two groups of identically-investigated patients, one consisting of 11 cases of cervical cancer (stage III), treated solely by irradiation and the other of 12 cases of cervical cancer (Stages I a and II b), treated by operation only. Before irradiation and in the non-irradiated group cellular immunity appeared to be more disturbed in cases of breast cancer than in cases of cervical carcinoma, as shown by the lowest number of lymphocytes, the lowest number of spontaneously-rosetting lymphocytes, the lowest percentage of DNCB sensitization in patients and the lowest percentage of Tuberculin-positive skin tests. In both types of carcinoma the humoral immunity appeared to be impaired, as apparent from the lowered immune response to tetanus vaccination. Other parameters of humoral immunity such as the immune globulin concentration, iso- and heteroagglutinine, the titre of measles antibodies or membrane fluorescence of lymphocytes showed no dinstinct trends during the investigation period. After irradiation a) inhibiting and b) stimulating influences were observed: a) The incidence and extent of the immune response to tetanus vaccination was further reduced and a distinct lymphopenic effect was observed. b) The incidence of positive skin tests with varidase, as well as the number of spontaneously-rosetting lymphocytes increased after the commencement of irradiation. Apart from the known sensitization with DNCB and skin tests with tuberculin, determination of the antitoxin titre before and after tetanus vaccination provided the most reliable results in regard to immunological reactivity in the investigated tumour patients.     

Reproducibility of continuous arterial spin labeling perfusion MRI after 7 weeks

Background Continuous arterial spin labeling (CASL) is a non-invasive technique for the measurement of cerebral blood flow (CBF). The aim of the present study was to examine the reproducibility of CASL measurements and its suitability to consistently detect differences between groups, regions, and resting states. Materials and methods Thirty-eight healthy subjects (19 female) were examined at 1.5 T on two measurement occasions that were seven weeks apart. Resting CBF was measured with eyes open and eyes closed. Results In different regions of interest (ROIs) the repeatability estimates varied between 9 and 19 ml/100 g/min. There were no significant mean differences between occasions in all ROIs (P > 0.05). Greater CBF in the eyes-open than in the eyes-closed state was consistently present in the primary and secondary visual areas. Furthermore, CBF was consistently greater in the right than in the left hemisphere (P < 0.05) and differed between lobes and between arterial territories (P < 0.001). Finally, we consistently observed greater CBF in women than in men (P < 0.001). Conclusion This study demonstrates the suitability of CASL to consistently detect differences between groups, regions, and resting states even after seven weeks. This emphasizes its usefulness for longitudinal designs.     

Microbial dehalogenation of trichlorinated dibenzo-p-dioxins by a Dehalococcoides-containing mixed culture is coupled to carbon isotope fractionation

An anaerobic enrichment culture reductively dehalogenated 1,2,4- and 1,2,3-trichlorodibenzo-p-dioxin (TrCDD) almost exclusively at peripheral positions forming the main products 1,3-dichloro-(DiCDD) and 2-monochlorodibenzo-p-dioxin (MCDD) from 1,2,4-TrCDD and 2,3-DiCDD from 1,2,3-TrCDD. Dehalococcoides was monitored in the mixed culture by quantitative real-time PCR. A yield of 2.5 x 10(8) to 2.75 x 10(8) copies of 16S rRNA genes per micromole of chloride released suggested growth by dehalorespiration with dibenzo-p-dioxins. For the analysis of carbon isotope fractionation, the dioxin congeners were isolated by solid-phase microextraction (SPME) from the headspace of the cultures. The delta13C composition of 1,2,4-TrCDD did not change remarkably during the course of reductive dehalogenation; however, the intermediate 1,3-DiCDD became enriched, and the final product 2-MCDD significantly depleted in 13C with a discrimination of 2.5-3.6 per thousand between 1,3-DiCDD and 2-MCDD. 1,2,3-TrCDD and its main product 2,3-DiCDD became slightly enriched in 13C, whereas the formed low concentrations of 2-MCDD were depleted in 13C by 5.5-4.8 per thousand. This study demonstrates carbon isotope fractionation during sequential reductive dehalogenation of chlorinated dibenzo-p-dioxins, whereby isotope fractionation upon dehalogenation of the intermediate was substantial. This can provide a basis for the development of a new method to monitor the fate of dioxins in the environment using compound specific stable isotope analyses.