Ann Lindgård

A segmentation technique to determine fat content in NMR images of beef meat

There is a constant need for new methods of meat-quality evaluation. Recent advances in the area of computer and video processing have created new ways to monitor quality in the food industry. In this paper, we describe an image-processing technique to determine fat content in beef meat. To achieve this, nuclear magnetic resonance (NMR) images of beef meat have been used. The inherent advantages of NMR images are many. Chief among these are unprecedented contrasts between the various structures present in meat, such as muscle, fat, and connective tissue. Moreover, the three-dimensional nature of the NMR method allows the analysis of isolated cross-sectional slices of the meat and the measure of the volumetric content of fat, and it is not limited to measurements of the superficially visible fat. We propose a segmentation algorithm for the detection of fat and a filtering technique to remove intensity inhomogeneities in NMR images, caused by nonuniformities of magnetic field during acquisition. Measurements have been successfully correlated with chemical analysis and digital photography. We also propose a method to quantify the distribution of fat. Our results show that the NMR technique is a promising noninvasive method to determine fat content in meat.

Preservation of rat skeletal muscle energy metabolism by illumination

Skeletal muscle viability is crucially dependent on the tissue levels of its high energy phosphates. In this study we investigated the effect of the preservation medium Perfadex and illumination with Singlet Oxygen Energy (SOE). Singlet oxygen can be produced photochemically by energy transfer from an excited photosensitizer. The energy emitted from singlet oxygen upon relaxation to its triplet state is captured as photons at 634 nm and is here referred to as SOE. Rat hind limb rectus femoris muscles were preserved for five hours at 22 degrees C in Perfadex, saline, SOE illuminated Perfadex or SOE illuminated saline. Extracts of the muscles were analysed by 31P NMR. Data were analysed using two-way analysis of variance and are given as mean values micromol/g dry weight) +/- SEM. The ATP concentration was higher (p = 0.006) in saline groups (4.52) compared with Perfadex groups (2.82). There was no statistically significant difference in PCr between the saline groups (1.25) and Perfadex groups (0.82). However, there were higher (p = 0.003) ATP in the SOE illuminated groups (4.61) compared with the non-illuminated groups (2.73). The PCr was also higher (p < 0.0001) in the SOE illuminated groups (1.89) compared with the non-illuminated groups (0.18). In conclusion, Perfadex in this experimental model was incapable of preserving the high energy phosphates in skeletal muscle during 5 hours of ischemia. Illumination with SOE at 634 nm improved the preservation potential, in terms of a positive effect on the energy status of the muscle cell.

Testing MRI and image analysis techniques for fat quantification in meat science

The world of meat faces a permanent need for new methods of meat quality evaluation. Recent advances in the area of computer and video processing have created new ways to monitor quality in the food industry. Here, the authors describe an image processing technique to determine fat content in beef meat. To achieve this NMR (Nuclear Magnetic Resonance) images of beef meat have been used. The inherent advantages of NMR images are many. Chief among these are unprecedented contrasts between the various structures present in meat, as muscle, fat, and connective tissue. Moreover, the three-dimensional nature of the NMR method allows the analysis of isolated cross-sectional slices of the meat and the measure of volumetric content of fat, no only the superficially visible one. The authors propose a segmentation algorithm for the detection of fat and a filtering technique to remove intensity inhomogeneities in NMR images, cause by non-uniformities of magnetic field during acquisition. Measurements have been successfully correlated with chemical analysis and digital photography. The authors also propose a method to quantify the distribution of fat. Their results show that NMR technique is a promising non-invasive method to determine fat content in meat.

Enhanced post‐ischaemic recovery in rabbit kidney after pretreatment with an indeno–indole compound and ascorbate monitored in vivo by 31P magnetic resonance spectroscopy

Objective: To investigate whether combined pretreatment with lipid‐ and water‐soluble antioxidants gave better restoration of energy phosphates after ischaemia–reperfusion of rabbit kidneys than single pretreatment with a lipid‐soluble antioxidant. Material and Methods: Thirteen New Zealand white rabbits were used for the study. Changes in energy phosphates were measured in vivo using volume‐selective 31 P magnetic resonance spectroscopy. The indeno–indole compound H290/51 was chosen as a lipid‐soluble antioxidant and ascorbate as a water‐soluble antioxidant. Results: The combined pretreatment led to significantly better restoration of the β‐adenosine triphosphate:inorganic phosphate ratio after 60 min of ischaemia and 120 min of reperfusion compared with the single pretreatment. Analyses of blood pressure and blood gas changes showed that the beneficial effect of combined pretreatment was not caused by a better general condition of the animals in that group but by a direct effect on the kidneys. Conclusions: Combined pretreatment with lipid‐ and water‐soluble antioxidants leads to better restoration of energy phosphates in rabbit kidneys subjected to ischaemia–reperfusion compared with single pretreatment with a lipid‐soluble antioxidant.

Aqueous fish extract increases survival in the mouse model of cytostatic toxicity

BackgroundTreatment of cancer patients with anthracycline antibiotic doxorubicin (DOX) may be complicated by development of acute and chronic congestive heart failure (CHF), malignant arrhythmias and death. The aim of this study was to test whether an aqueous low molecular weight (LMW) extract from cod muscle decreases acute mortality in the mouse model of acute CHF caused by DOX.MethodsA LMW fraction (<500 Da) of the aqueous phase of cod light muscle (AOX) was used for treatment of male BALB/c mice (~25 g, n = 70). The animals were divided into four groups, DOX + AOX (n = 20), DOX + saline (NaCl) (n = 30), NaCl + AOX (n = 10) and NaCl only (n = 10). Echocardiography was performed in the separate subgroups (DOX treated n = 6 and controls n = 6) to verify the presence and the grade of acute CHF. The cod extract was delivered by subcutaneously implanted osmotic minipumps over the period of 2 weeks. High-dose injection of DOX was administered to randomly selected animals. The animals received single intraperitoneal injection of DOX (25 mg/kg) and were followed over two weeks for mortality.ResultsMortality rate was 68% lower (p < 0.05) in the mice treated with the extract. The analyses of cod extract have shown strong antioxidative effect in vitro.ConclusionThe aqueous LMW cod muscles extract decreases mortality in the mouse model of DOX induced acute CHF. This effect may be mediated by cardioprotection through antioxidative mechanisms.

Transplanting embryonic stem cells onto damaged human corneal endothelium

AIM To investigate whether human embryonic stem cells (hESCs) could be made to attach, grow and differentiate on a human Descemet’s membrane (DM). METHODS Spontaneously differentiated hESCs were transferred onto a human corneal button with the endothelial layer removed using ocular sticks. The cells were cultured on a DM for up to 15 d. The genetically engineered hESC line expressed green fluorescent protein, which facilitated identification during the culture experiments, tissue preparation, and analysis. To detect any differentiation into human corneal endothelial-like cells, we analysed the transplanted cells by immunohistochemistry using specific antibodies. RESULTS We found transplanted cells form a single layer of cells with a hexagonal shape in the periphery of the DM. The majority of the cells were negative for octamer-binding transcription factor 4 but positive for paired box 6 protein, sodium potassium adenosine triphosphatase (NaKATPase), and Zona Occludens protein 1. In four of the 18 trials, the transplanted cells were found to express CK3, which indicates that the stem cells differentiated into corneal epithelial cells in these cases. CONCLUSION It is possible to get cells originating from hESCs to become established on a human DM, where they grow and differentiate into corneal endothelial-like cells in vitro.