Addition of various carbohydrates to beef burgers affects the formation of heterocyclic amines during frying

The influence of the addition of carbohydrates with different physicochemical properties on weight loss and formation of heterocyclic amines (HAs) during the frying of beef burgers was examined. Furthermore, the capability of carbohydrates to bind HAs was tested. Beef burgers containing 1.5% NaCl and 0.3% tripolyphosphate (reference), with the addition of 1.5% carbohydrate, were fried for 5 min at 200 degrees C in a double-sided pan fryer. The beef burgers were analyzed for HAs with solid phase extraction and liquid chromatography/mass spectrometry. 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP), and 9H-pyrido[3,4-b]indole (Norharman) were detected in all of the beef burgers. The addition of carbohydrates affected both the weight loss and the formation of HAs during cooking. The formation of HAs could be correlated to depend on both the weight loss and the type of the added carbohydrate. Of the 11 different carbohydrates tested, raw potato starch was most capable of inhibiting the formation of HAs, while potato fiber gave the lowest weight loss and a comparably low amount of PhIP. Wheat bran and potato fiber were found to reversibly bind HAs. It is concluded that adding small amounts of certain carbohydrates may be a simple and effective way of reducing the amount of HAs and can easily be applied in households and commercial preparations of beef burgers.     

Natural variations of precursors in pig meat affect the yield of heterocyclic amines--effects of RN genotype, feeding regime, and sex

Pig meat shows natural variations in the concentrations of precursors of heterocyclic amines (HCAs), which may affect formation of HCAs in cooked pig meat. To study this, 26 pigs with an inherent genetic variation (carriers and noncarriers of the RN(-) allele) were subjected to different feeding regimes (conventional feed compared with feed composed according to organic standards). In addition, the effect of sex (castrated males or females) was considered when assessing chemical and technological meat quality parameters. Concentrations of precursors of HCAs, i.e., creatine, residual glycogen, dipeptides, and free amino acids, were analyzed in the raw meat, and the levels of some HCAs (4,8-DiMeIQx, MeIQx, PhIP, harman, and norharman) were then determined in fried meat patties prepared from these pigs. The RN genotype most affected technological meat quality parameters and the level of precursors of HCAs, especially the level of residual glycogen, where carriers of the RN(-) allele showed levels four times as high as those of noncarriers (75.3 +/- 2.6 compared with 17.2 +/- 2.4 micromol/g meat, least-squares means +/- SE). The increased level of residual glycogen resulted in about 50% lower amounts of total mutagenic HCAs in cooked meat compared with cooked meat from normal pigs. Fried meat from carriers of the RN(-) allele obtained darker crust color than meat from noncarriers. Feeding regime and sex did not significantly affect the chemical composition of the meat or the formation of HCAs.     

A new resorbable device for ligation of blood vessels - A pilot study

Background

During surgery, controlled haemostasis to prevent blood loss is vital for a successful outcome. It can be difficult to ligate vessels located deep in the abdomen. A device that is easy to use and enables secure ligatures could be beneficial. Cable ties made of nylon have been used for ligation but the non-resorbable material caused tissue reactions. The objective of this study was to use a resorbable material to construct a device with a self-locking mechanism and to test its mechanical strength and ligation efficiency.

Methods

The device was manufactured by injection moulding of polydioxanone, a resorbable polymer used for suture materials. Polydioxanone with inherent viscosities of 1.9 dL/g and 1.3 dL/g were tested. The device consisted of a perforated flexible band which could be pulled through a case with a locking mechanism. After a first version of the device had been tested, some improvements were made. The locking case was downsized, corners were rounded off, the band was made thicker and the mould was redesigned to produce longer devices. Tensile tests were performed with the second version.The first version of the device was used to ligate the ovarian pedicle in a euthanized dog and to test echogenicity of the device with ultrasound. Compression of vessels of the ovarian pedicle was examined by histology. Both versions of the device were tested for haemostasis of and tissue grip on renal arteries in six anaesthetised pigs.

Results

The tensile strength of the flexible band of the devices with inherent viscosity of 1.9 dL/g was 50.1 ± 5.5 N (range 35.2-62.9 N, n = 11) and the devices with inherent viscosity of 1.3 dL/g had a tensile strength of 39.8 ± 8.1 N (range 18.6-54.2 N, n = 11). Injection moulding of the polymer with lower inherent viscosity resulted in a longer flow distance.Both versions of the device had an effective tissue grip and complete haemostasis of renal arteries was verified. The device attached to the ovarian pedicle could be seen with ultrasound, and vessel compression and occlusion were verified by histology.

Conclusions

Tests of functionality of the device showed complete haemostasis and good tissue grip. Devices with a band of sufficient length were easily applied and tightened in tissue.     

Molecular detection of nematode predation and scavenging in oribatid mites: Laboratory and field experiments

Recent stable isotope analyses indicate that a number of putative detritivorous soil microarthropods is not typical detritivores but rather live as predators or scavengers. Using molecular gut content analyses the present study investigates if nematodes indeed form part of the diet of oribatid mites. First, in a no-choice laboratory feeding experiment two nematode species (Phasmarhabditis hermaphrodita and Steinernema feltiae) were offered to eight species of oribatid mites and one gamasid mite. Second, after feeding for 4 and 48 h on each nematode species the detection time of prey DNA in the oribatid mite species Steganacarus magnus was investigated. Third, in a field experiment nematode prey (P. hermaphrodita and S. feltiae) in the diet of microarthropods was investigated distinguishing between scavenging and predation. In the no-choice laboratory experiment not only the gamasid mite but also several of the studied oribatid mite species consumed nematodes. After feeding on nematodes for 4 h prey DNA was detectable in S. magnus for only 4 h, but after feeding for 48 h prey DNA was detectable for 128 h, indicating that the duration of feeding on prey is an important determinant for prey DNA detection. The field experiment confirmed that oribatid mite species including Liacarus subterraneus, Platynothrus peltifer and S. magnus intensively prey on nematodes. Interestingly, DNA of dead P. hermaphrodita was detectable to a similar degree as that of living individuals indicating that scavenging is of significant importance in decomposer food webs. Results of our study indicate that predation and scavenging on nematodes by “detritivorous” microarthropods in soil food webs need to be reconsidered.     

The apoplast — its significance for the nutrition of higher plants

Since the fundamental work of the botanist Ernst Munch there has been a clear differentiation between a symplastic and an apoplastic compartment of plants, separated by the plasmalemma. In contrast to the symplast, the apoplast was considered as being dead and hence attracted little interest. It is not before the late seventies of this century that plant scientists realised that processes such as growth and differentiation as well as signal transduction may not be understood without accounting for apoplastic processes. Since then growing evidence has supported the view that apoplastic properties are of significance for such diverse processes as genotypic variation in nutrient efficiency and tolerance against adverse ion relations, for plant/microbe interaction, or for water and nutrient transport. In this contribution we review apoplastic properties and processes in relation to plant mineral nutrition. Examples are taken from work being conducted in the scope of the special research project of the German Research Foundation “The apoplast of higher plants: compartment for storage, transport and reactions” and especially from own work.     

Heart Sounds and Murmurs: Changes Related to Severity of Chronic Valvular Disease in the Cavalier King Charles Spaniel

Auscultatory, phonocardiographic (PCG), radiographic, and echocardiographic evidence of chronic valvular disease (CVD) were studied in 79 Cavalier King Charles Spaniels with a mean age of 7.6 years (SD 2.6). Cardiac murmurs were present in 59 of the dogs and the intensity of the systolic cardiac murmur, assessed by auscultation (grade 1–6), was correlated (P < .001) to the severity of CVD (heart failure class) and to the echocardiographical dimensions of the heart (left atrial ratio, La/Ao-d, and left ventricular end diastolic diameter, LVEDD) (both P < .001). The heart sounds and duration of electromechanical systole (Q-S2) were investigated in all dogs using measurements obtained from PCG recordings. Normal regression equations describing the relation between heart rate and systolic intervals (Q-S1, Q-S2 and S1-S2) were established based on observations in 11 normal control Cavalier King Charles Spaniels. The total electromechanical systole (Q-S2), Q-S1, and S1-S2 intervals in the 59 dogs were related to the corresponding normal regression equation. A shortening of Q-S2 and S1-S2 intervals were found in dogs belonging to heart failure class I (Q-S2; P < .01 and S1 -S2; P < .05), class II, and classes III and IV (both P < .001). The ratio of the amplitudes of the first (S1) and second heart sounds (S2) measured on the PCG recordings was found to be increased in dogs belonging to class I (P < .01), class II, and classes III and IV (both P < .001). The relationship between cardiac dimensions (LVEDD and La/Ao-d) and S1a/S2a ratio was described by quadratic regression and found to be significant for both parameters (LVEDD; P < .001, R²= .54 and La/Ao-d; P < .001, R²= .63). The presence of a third heart sound (S3) was detected, using PCG, in 21 of the 68 dogs. The proportion of dogs exhibiting S3 increased with heart failure class (and increasing cardiac dimensions) (P < .001). These findings were confirmed by observations in 13 Cavalier King Charles Spaniels with cardiac failure progressing from heart failure class I to class II (Mean LVEDD from 30.2 to 35.2 mm and mean La/Ao-d from 1.09 to 1.43). An increase in intensity of the heart murmur, assessed by auscultation, increase in the ratio of the amplitudes of S1 and S2, as well as a shortening in Q-S2 and S1-S2 intervals (all P < .01) were found in these dogs. None of these dogs showed an S3 in heart failure class I, but 7 of the 13 dogs developed an S3 in class II.     

Bacteriological and virological status in upper respiratory tract infections of cats (cat common cold complex)

Between October 2002 and January 2005,460 bacteriological samples from cats with an acute upper respiratory tract infection were analysed in clinical field studies in two accredited laboratories in Germany. Oropharyngeal swabs were taken from these cats and sent to the laboratories for routine diagnostics. In the swab samples of 460 cats 382 bacteria strains were isolated.The following bacteria were isolated most frequently: Pasteurella spp. (32.5 %), Staphylococcus spp. (18.5 %), Escherichia coli (17.0 %), Streptococcus spp. (9.1 %), Pseudomonas spp. (6.9 %) and Klebsiella spp. (3.0 %). Bordetella bronchiseptica was found in 0.4 % of the animals To evaluate possible regional and time influences, the animals were split into three populations: 1: Germany, laboratory A; 2: Germany, laboratory B; 3: France and Belgium, laboratory B. In population 1 an 2 Pasteurella spp. were found most frequently with 42.2 % and 36.5 %, respectively.The second most frequently isolated bacterial species were Staphylococcus spp. with 14.1 % and 21.4 % and E. coli with 13.6 % and 17.5 % respectively. In population 3 Staphylococcus spp., E. coli (20 % each) and Pasteurella spp. (18.5 %) were isolated at almost the same frequency. Virological parameter were additionally analysed in 328 cats (population 2 and 3). Serum samples were analysed for antibodies specific for Feline Calicivirus (FCV) and Feline Immunodeficiency Virus (FIV) and for Feline Leukaemia Virus (FeLV) antigen. Oropharyngeal swabs were analysed for Feline Herpesvirus (FHV) by using PCR. Calicivirus-specific antibodies were found in 99.6 % of the cats of population 2 and in 100 % of the animals in population 3. Herpesvirus was detected in 15.3 % and 23.3 % of the cats, respectively. FeLV-Antigen was found in 0.4 % of the animals in population 2 and in 10.1 % of the cats in population 3, while FIV-antibodies were identified in 8.7 % of the animals of population 2 and in 6.1 % of the cats of population 3. In total FHV was found in 19.3 % and FCV-specific antibodies in 99.7 % of the animals. 5.3 % of the cats carried FeLV-Antigen, and 7.4 % FIV-specific antibodies. The results of the bacteriological analysis as well as the results of the virological examination confirm previously published data. In this study Pasteurella spp. were most frequently isolated (32.5 %).     

Optimised use of data fusion and memory-based learning with an Austrian soil library for predictions with infrared data

Infrared spectroscopy in the visible to near-infrared (vis–NIR) and mid-infrared (MIR) regions is a well-established approach for the prediction of soil properties. Different data fusion and training approaches exist, and the optimal procedures are yet undefined and may depend on the heterogeneity present in the set and on the considered scale. The objectives were to test the usefulness of partial least squares regressions (PLSRs) for soil organic carbon (SOC), total carbon (C_t), total nitrogen (N_t) and pH using vis–NIR and MIR spectroscopy for an independent validation after standard calibration (use of a general PLSR model) or using memory-based learning (MBL) with and without spiking for a national spectral database. Data fusion approaches were simple concatenation of spectra, outer product analysis (OPA) and model averaging. In total, 481 soils from an Austrian forest soil archive were measured in the vis–NIR and MIR regions, and regressions were calculated. Fivefold calibration-validation approaches were carried out with a region-related split of spectra to implement independent validations with n ranging from 47 to 99 soils in different folds. MIR predictions were generally superior over vis–NIR predictions. For all properties, optimal predictions were obtained with data fusion, with OPA and spectra concatenation outperforming model averaging. The greatest robustness of performance was found for OPA and MBL with spiking with R² ≥ 0.77 (N), 0.85 (SOC), 0.86 (pH) and 0.88 (C_t) in the validations of all folds. Overall, the results indicate that the combination of OPA for vis–NIR and MIR spectra with MBL and spiking has a high potential to accurately estimate properties when using large-scale soil spectral libraries as reference data. However, the reduction of cost-effectiveness using two spectrometers needs to be weighed against the potential increase in accuracy compared to a single MIR spectroscopy approach.