1H NMR-based metabolomics profiling and taste of stewed pork-hock in soy sauce.

Stewed pork-hock in soy sauce is a representative meat product in China. Its taste quality is highly related to primary and secondary metabolites. This study researched the effects of stewing points (0, 30, 60 and 90 min) on the metabolites profile variation of stewed pork-hock in soy sauce by using 1H NMR spectroscopy with multivariate data analysis. The metabolome consisted of 25 metabolites, including amino acids, sugars, organic acids, nucleic acids and their derivatives. PC1 and PC2 explained a total of 90% and 7.8% of variables, respectively. Most amino acids, sucrose, ß-glucose, acetate and creatinine increased during stewing, while creatine decreased. Fumarate kept extremely low content during the whole stewing process. The 60 and 90 min stewed points owned relatively higher levels of metabolites and sensory evaluation compared to other points. These results indicated that 1H NMR-based metabolomics is useful for a better understanding on the change of meat products during the stewing process, thus improving the stewing time to provide a better taste and higher product sales of stewed pork-hock in soy sauce.

Methionine-enkephalin in bone and joint tissues.

Methionine-enkephalin (met-enk), an endogenous opiate, mimics many of the effects of morphine by binding to opiate receptors, thereby eliciting similar cellular and behavioral effects. Using biochemical and immunohistochemical techniques, several peptides have been identified in bone and joint tissues. Here we report, for the first time, the presence as well as concentration of met-enk in bone and joint tissues. Immunohistochemistry using electron and immunofluorescence microscopy showed cellular and neuronal distribution of met-enk in bone and joint tissues. The concentration of met-enk analyzed by high performance liquid chromatography electrochemical detection or radioimmunoassay was high in bone marrow, periosteum, ankle joint tissue, and cortical bone. Analysis by fast atom bombardment mass spectrometry suggested that the recovered fragment was met-enk Administration of met-enk inhibits osteoblast cell growth in culture, which is reversible by naltrexone. In arthritic rats, the concentration of met-enk was significantly decreased in ankle joints compared with controls, suggesting a role for met-enk in the pathophysiology of adjuvant arthritis.

Effects of surgical denervation on substance P and calcitonin gene-related peptide in adjuvant arthritis.

The occurrence of substance P (SP) and calcitonin gene-related peptide (CGRP) was assessed in the ankle joints and dorsal root ganglia (L2-L6) by immunohistochemistry and radioimmunoassay (RIA) after unilateral sciatic nerve section in adjuvant arthritis. Nerve section in arthritic rats had no clear-cut effect on warmth, redness, and swelling of ankle joints, but significantly affected the occurrence of SP and CGRP. Immunohistochemical analysis showed an almost complete disappearance of SP-positive fibers in the ipsilateral ankle joint in normal rats after axotomy, whereas in arthritic rats occasional SP-positive fibers remained. In dorsal root ganglia, only occasional SP-positive cells could be detected in normal and arthritic rats after axotomy. A similar but somewhat less pronounced effect of axotomy was noted for neuronal CGRP-LI. RIA showed a decrease in SP in ankle joints by 45% in normal rats and 58% in arthritic rats; the decrease in CGRP was 41% and 47%, respectively. In dorsal root ganglia, the decrease in SP after surgical denervation was 25% in normal rats and 54% in arthritic rats; the decrease in CGRP was 18% and 27%, respectively. The tissue concentrations of SP and CGRP in ipsilateral ankle joints and dorsal root ganglia were consistently correlated in normal as well as arthritic rats. The present study shows that an interruption of the nerve supply to joints cannot fully prevent the development of arthritis, although it significantly reduces the occurrence of sensory neuropeptides.

Relationships between the bone pathologies, ash and mineral content of long bones in 35-day-old broiler chickens.

Histological examinations and estimations of the contents of ash, phosphorus and calcium were used to investigate the femora and tibiotarsi from lame and normal 35-day-old broilers from Holland, Northern Ireland and Scotland. The prevalence of different pathologies varied with the source of the broilers and there were correlations between histological and bone ash values. The most common condition causing lameness was bacterial infection within the physis and cartilaginous epiphysis (bacterial chondronecrosis) of the proximal tibiotarsus, and there was a possible link between rickets attributable to a relative phosphorus deficiency and this condition. There were wide variations between birds in the cortical bone quality as assessed histologically and by estimates of the bone ash content and phosphorus to calcium ratios. Theses variations may be related to different probabilities of bone fracture.

Comparative study of the angle-resolved backscattering properties of collagen fibers in bovine tendon and cartilage.

In a biological tissue, light scattering is based on the size and type of scatterers seen as refractive index variations that describe the optical properties shown. In this paper, we have implemented the variable incidence angle technique of multiple angle of illumination experiment on tendon and cartilage samples whose dominant constituents are genetically different types of collagen fibers, type I and type II, respectively. It is found that tendon displays a much greater angular anisotropy in its optical backscattering coefficient than the healthy cartilage. We propose that this is due to a more uniform distribution of fine fibrils than is found in tendon. Rayleigh-Gans approximation is used to give qualitative support to this idea.

[Fluorine and calcium concentrations in bones of the wood pigeon from the environs of Szczecin: a 2002-2004 study]. / Steenia fluoru i wapnia w kosciach grzywacza z okolic szczecina w latach 2002-2004.

MATERIAL AND METHODS: This study was done in 176 wood pigeons (Columba palumbus). In 2002, assays were performed on 24 immature (imm) and 66 adult (ad) individuals. In 2003, 15 immature birds could be assayed, while the 2004 sample consisted of a total of 71 individuals (12 imm and 59 ad). Pigeons were caught near the villages of Skarbimierzyce and Doluje situated west of Szczecin. Fluorine and calcium content in ash and dry mass of the wood pigeon's tarsometatarsus bones was determined. Fluorine content in ash and dry mass increased with age of the bird. It was only in 2002 samples that significant differences between immature and adult pigeons in calcium ash content were detected. Analysis of variance (ANOVA) failed to reveal significant differences between 2002 and 2004 samples in calcium content of adult bone ash. The remaining parameters in this group of birds differed significantly. The immature group showed no significant differences between 2002 and 2004 samples in fluorine content of bone ash and dry mass. Significant differences (p < 0.01) in fluorine content were revealed between 2002 and 2003 as well as between 2003 and 2004 samples. Ash calcium content showed no differences for immature birds of 2002 and 2003; however, significant differences (p < 0.001) were revealed between 2002 and 2004 as well as between 2003 and 2004. No significant differences were revealed between the immature bone dry mass calcium contents in 2002 and 2003 as well as in 2002 and 2004; on the other hand, the difference between the 2003 and 2004 data proved significant (p < 0.05). RESULTS: The present study demonstrated a number of differences in fluorine and calcium content in bones of the plant-eating wood pigeon. In addition, fluorine was found to undergo an intense age-related accumulation in bones. Fluorine content showed marked year-to-year variability. CONCLUSIONS: It is highly probable that fluorine content in wood pigeon bone reflects environmental fluorine contamination from industrial plants in Szczecin and its environs which are the major source of fluorine emissions.

Collagen types IX and X in the developing chick tibiotarsus: analyses of mRNAs and proteins.

To examine the regulation of collagen types IX and X during the hypertrophic phase of endochondral cartilage development, we have employed in situ hybridization and immunofluorescence histochemistry on selected stages of embryonic chick tibiotarsi. The data show that mRNA for type X collagen appears at or about the time that we detect the first appearance of the protein. This result is incompatible with translational regulation, which would require accumulation of the mRNA to occur at an appreciably earlier time. Data on later-stage embryos demonstrate that once hypertrophic chondrocytes initiate synthesis of type X collagen, they sustain high levels of its mRNA during the remainder of the hypertrophic program. This suggests that these cells maintain their integrity until close to the time that they are removed at the advancing marrow cavity. Type X collagen protein in the hypertrophic matrix also extends to the marrow cavity. Type IX collagen is found throughout the hypertrophic matrix, as well as throughout the younger cartilaginous matrices. But the mRNA for this molecule is largely or completely absent from the oldest hypertrophic cells. These data are consistent with a model that we have previously proposed in which newly synthesized type X collagen within the hypertrophic zone can become associated with type II/IX collagen fibrils synthesized and deposited earlier in development (Schmid and Linsenmayer, 1990; Chen et al. 1990).

Collagen biochemistry of avian bone: comparison of bone type and skeletal site.

1. Skeletal disorders in poultry are of considerable welfare and economic importance. The collagenous matrix in bone is involved in many human skeletal disorders, however little is known about the nature of the collagenous matrix in avian bone. 2. This paper describes an investigation of the collagen and mineral biochemistry together with the biomechanics of bone from different sites (humerus and tibiotarsus) and with differing functions (medullary and cortical bone). In vivo and in vitro studies of immature bone assessed the changes in collagen biochemistry during bone maturation. 3. The material strength of the humerus was greater than the tibiotarsus; this difference in strength was reflected in both the collagen and mineral matrix biochemistry. 4. The bone matrix of the humerus was more mature than that of the tibiotarsus, suggesting a higher level of matrix turnover in the tibiotarsus. The pyrrole collagen cross-link concentrations were positively correlated with breaking stress, in contrast to the pyridinoline cross-link concentrations, neither of which showed any correlation with bone strength. 5. The in vivo and in vitro maturation studies underline the importance of the pyrrole cross-link in avian bone and support the mechanism postulated by Kuypers et al. (1992) for the formation of the pyrrole cross-link from a lysine aldehyde and the immature cross-links HLKNL or LKNL. 6. Medullary bone had no biomechanical influence on the breaking stress of the bone. The biochemistry of the matrix was dramatically different. The high level of collagen lysine hydroxylation affected the cross-link profile and may be responsible for the narrow fibrils and disorganised matrix of this bone. 7. Avian bone matrix varies greatly with skeletal site and reflects the differing functions of bone. Further investigation of the collagenous matrix of both normal and diseased avian bone has the potential to aid our understanding of the aetiology of avian skeletal disease.