Early post-mortem sarcoplasmic proteome of porcine muscle related to protein oxidation.

Oxidative deterioration or modifications of proteins which appear during meat storage and processes can result in the impairment of technological, sensorial and nutritional qualities. Improving the quality involves a better understanding of the biochemical mechanisms responsible for protein oxidation in meat. For that purpose, an analysis was conducted to investigate the relationships between the early post-mortem sarcoplasmic proteome, which contains the majority of enzymes involved in the oxidative process, and protein oxidation generated during meat storage and cooking. This study was performed in Longissimus lumborum pig muscle. In order to have sufficient variability in the proteome and in the meat oxidation level, five groups of 10 animals issued from two different breeds and raised in three different rearing systems were analysed. Protein oxidation was estimated by the measurement of carbonyl groups after 1 and 4days of refrigerated storage, and after 100°C experimental cooking of the 4days aged meat. Significant correlations (p<0.05) were observed between the level of carbonyl groups and the intensities of 104 spots of the 2D electrophoresis, out of which 52 were clearly identified. The possible involvement of some proteins in the muscle oxidative stress leading to protein oxidation is discussed.

Participation in breast screening programs: a review.

Despite recommendations by the American Cancer Society and other organizations for use of screening mammography, data on reported utilization of this procedure by American women show that these guidelines are not being met. We reviewed published studies that reported participation rates or that examined factors associated with participation in selected breast screening programs. In general, women at high risk due to age and family or personal history of breast disease were not more likely to participate in breast screening programs than women without those risk factors. The one group of variables that was fairly consistently associated with participation was the practice of other preventive health behaviors. Women who expressed more concern about their health and who were more knowledgeable about breast cancer screening and its benefits also were more likely to complete mammography. Approaches to increasing participation are discussed in the context of the literature on this subject.

Spatial distribution of myosin heavy chain isoforms and lactate dehydrogenase M4 in the limb musculature of two crossbred lambs.

Sixteen different skeletal muscle samples were distributed in the cross-section of eight hip and thigh muscles. Contractile characteristics were assessed by measuring myosin heavy chain (MHCI, MHCIIa, MHCIIb) composition by electrophoresis. Glycolytic capacity was estimated by immunochemical quantitation of the LDH-M4. Histochemistry was used as a reference. The MHC isoform composition of most of the muscles in this study was heterogeneous. When an intramuscular transversal regionality was observed (semitendinosus, vastus lateralis, vastus medialis and rectus femoris muscles), MHCI percentage increased toward deeper layers, while MHCIIb and LDH-M4 decreased. The pattern of MHCIIa isoform distribution was less evident. Within semimembranosus and gluteus medius muscles, proportions of MHC isoforms were constant. Gradients of variation of MHCI and MHCIIb isoforms across rectus femoris and vastus medialis muscles were sharper than those of semitendinosus and vastus lateralis muscles. For the vastus lateralis muscle, these gradients may also be modified according to the breed. Breed effect was mainly shown by MHCIIb and MHCI isoforms and was not observed at all the sampling points of the muscles. These observations show that breed effect on muscle contractile and metabolic characteristics is not uniformly expressed throughout the muscle. Results of a comparison may differ according to the muscle and sampling location.

Prediction of composition traits of young Charolais bull carcasses using a morphometric method.

The relationships among morphological traits and bovine carcass composition traits were analysed in order to select carcass measurements to derive equations for predicting muscle weight, percentage of muscle and muscle to bone ratio. The sample, constituted by 35 young Charolais bulls slaughtered at 18 months old, was homogeneous, e.g. half carcass weight = 225 ± 13.2 kg (standard deviation), carcass fat% = 6.4 ± 1.0, carcass muscle% = 74.58 ± 1.47, carcass bone% = 16.87 ± 0.83. Carcasses were weighed and a sub-group of carcass measurements was selected from the results of a principal component analysis, performed on 76 measurements taken from carcass photographs. The computation of the best combination of variables for prediction was based on the Mallows' Cp statistic and linear regression. The percentage of muscle was best predicted by only three carcass measurements with a relatively low value of fit (R(2) = 0.70). When carcass weight was added to the same measurements to obtain the best prediction for muscle weight, the fit was high (R(2) = 0.98). The prediction of muscle to bone ratio required nine variables and again the fit was high (R(2) = 0.90).

Estimation of the muscle to bone ratio of the bovine pelvic limb using a morphometric method.

Conformation is an indicator of carcass composition. The aim of this study was to derive an equation for estimating the composition of the bovine pelvic limb using morphometric variates. From a mixed group of 38 French bred bovines, the sample was chosen to have a wide range of conformation. The muscle to bone ratio (M B ) was used as an index of composition. The carcasses were weighed and the other variates of the equation were measured on carcass photographs: M B = 6.2 + 0.005W - 0.62EF AB + 12GH with W: carcass weight (kg); GH: medio-lateral diameter of the distal part of the leg (cm); EF AB : medio-lateral diameter of thigh (cm)/leg length(cm); (R(2) = 0.91 and rsd = 0.27).

Efficacy of psychoeducational interventions on pain, depression, and disability in people with arthritis: a meta-analysis.

Meta-analysis is a technique which combines data from several properly and similarly designed controlled studies so as to increase the power of the relevant statistical analysis. Fifteen studies on the effects of psychoeducational interventions on disability, pain and depression in individuals with chronic rheumatoid arthritis or osteoarthritis were analyzed by this method. The results indicate that patient education can indeed contribute to improving the health status of such patients.

Early post-mortem sarcoplasmic proteome of porcine muscle related to lipid oxidation in aged and cooked meat.

In order to identify specific markers of lipid oxidation generated in meat during refrigerated storage and cooking an analysis was conducted to investigate the relationships between the early post-mortem sarcoplasmic proteome, which contains the majority of enzymes involved in the oxidative process, and the level of lipid oxidation. This study was performed in Longissimus lumborum pig muscle. Proteome was analysed by 2-D electrophoresis in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS) and lipid oxidation was estimated by the TBA reactive substances (TBA-RS) measurement. Many markers of lipid oxidation were identified, but no single marker covered the oxidative process in its entirety. The role of five protein groups (albumin, redoxins, annexins, lipid transporters and enzymes of aerobic respiration), from which a link with lipid oxidation can be established, is discussed. This study, which completes a precedent work focused on protein oxidation, clearly demonstrates that a combination of several markers is needed to assess the sensitivity of meat to oxidation during both ageing and cooking.

Estimation of genetic trends in French Large White pigs from 1977 to 1998 for growth and carcass traits using frozen semen.

Genetic trends for growth, feed efficiency, composition, and morphometry of carcasses were estimated in a French Large White (LW) pig population using frozen semen. Two groups of pigs were produced by inseminating LW sows with either stored, frozen semen from 17 LW boars born in 1977 or with semen from 23 LW boars born in 1998. In each group, 15 males and 90 females were randomly chosen and mated to produce approximately 1,000 pigs/group. These pigs were performance tested with individual ADFI and serial BW and backfat thickness measurements, slaughtered at 105 kg of BW, and measured for carcass traits. The data were analyzed using mixed linear animal models, including the fixed effect of the experimental group (offspring of 1977 or 1998 boars), the random effect of the additive genetic value of each animal, and, when significant, the fixed effects of sex, fattening batch, and slaughterhouse, the linear regression on BW, and the random effect of the common environment of birth litter. For each trait, the genetic trend was estimated as twice the difference between the 2 experimental groups. Results showed moderately favorable trends for on-test ADG (3.7 +/- 1.3 g/d per year) and feed conversion ratio (-0.014 +/- 0.005 kg/kg per year) in spite of a tendency toward an increase in ADFI (7.6 +/- 4.7 g/yr). A strong reduction in carcass fatness (-0.35 +/- 0.07 mm/yr for carcass average backfat thickness) and a large improvement in carcass leanness (0.31 +/- 0.10 mm(2)/yr and 0.41 +/- 0.08%/yr for loin eye area and carcass muscle content, respectively) were observed. Carcass shape measurements (back and leg length, back width, muscle thickness of hind limbs) were not affected by selection. Serial measurements of BW and backfat thickness showed that the major part of the genetic gains occurred during late growth and that the reduction in the backfat layer was more pronounced in the rear than in the front part of the carcass. The use of frozen semen appears to be a powerful practice to thoroughly investigate changes attributable to selection.

Proteomic analysis of ovine muscle hypertrophy.

Two-dimensional electrophoresis was used to investigate the effects of a QTL for muscle hypertrophy on sarcoplasmic protein expression in ovine muscles. In the Belgian Texel breed, the QTL for muscle hypertrophy is localized in the myostatin-encoding gene. Based on microsatellite markers flanking the myostatin gene, we compared the hypertrophied genotype with the normal genotype. The average age of the sheep was 3 mo. Among the 4 muscles studied, in the hypertrophied genotype only the vastus medialis was normal, whereas the semimembranosus, tensor fasciae latae, and LM were hypertrophied. In the hypertrophied genotype, these muscles showed upregulation of enzymes involved in glycolytic metabolism together with oxidative metabolism in LM. Certain chaperone proteins, including glutathione S-transferase-Pi, heat shock protein-27, and heat shock cognate-70, were also more highly expressed, probably due to increased use of energetic pathways. Expression of the iron transport protein transferrin was increased. Alpha-1-antitrypsin was the only protein showing a similar pattern of expression (i.e., less expressed) in all 4 muscles of the hypertrophied genotype. It is suggested that transferrin and alpha-1-antitrypsin may interact to reinforce myogenic proliferative signaling.

Polymorphic microRNA-target interactions: a novel source of phenotypic variation.

Studying the muscular hypertrophy of Texel sheep by forward genetics, we have identified an A-to-G transition in the 3'UTR of the GDF8 gene that reveals an illegitimate target site for microRNAs miR-1 and miR-206 that are highly expressed in skeletal muscle. This causes the down-regulation of this muscle-specific chalone and hence contributes to the muscular hypertrophy of Texel sheep. We demonstrate that polymorphisms which alter the content of putative miRNA target sites are common in human and mice, and provide evidence that both conserved and nonconserved target sites are selectively constrained. We speculate that these polymorphisms might be important mediators of phenotypic variation including disease. To facilitate studies along those lines, we have constructed a database (www.patrocles.org) listing putative polymorphic microRNA-target interactions.

Comparison of participants and nonparticipants in a work site cancer awareness and screening program.

In 1985, Pennzoil Company offered a company-paid cancer awareness and screening program focusing on breast and colorectal cancers for its employees. Following a lecture/slide presentation, employees filled out a risk assessment questionnaire. Those at risk for breast and/or colorectal cancers were invited for consultation, mammography, and/or short colonoscopy. Overall completion rates were 49% for mammography, 20% for the fecal occult blood test, and 31% for short colon oscopy, but these rates varied by risk status. Moreover, the same demographic and risk factors were not consistently associated with completion of the same screening procedure across risk groups. Based on these findings, we suggest that different interventions may need to be developed depending on the risk characteristics of subgroups within the target population.

[The mechanism of digging in Arvicola terrestris and Spalax ehrenbergi: functional and evolutional studies]. / Les mécanismes du fouissage chez Arvicola terrestris et Spalax ehrenbergi: étude fonctionelle et évolutive.

The cineradiographic study of the digging modalities in Arvicola terrestris and Spalax erenbergi showed important convergences in the mechanisms used by both species. Head and incisors are the burrowing tools, acting as a "scraping-shovel" in Spalax and as a "scratching-shovel" in Arvicola. They are moved forward by a force originated by the pressure of the hind limbs against the ground, and transmitted through the vertebral axis. The myological study of these species revealed the increase of the insertional areas for the cephalic muscles. However, the adaptative answer of the cervical vertebrae to the mechanical constraints of digging are different in Arvicola and Spalax; the former developed high resistance moments and the latter increased vertebral stiffness. The characters of the post-cranial skeleton in the digging rodents tend to constitute a morphocline in which Spalax is the final stage and Arvicola an intermediate stage. Then, the adaptative divergences noted above between these animals might reflect their phyletic distance.

The Texas Breast Screening Project: Part II. Demographics, risk profiles, and health practices of participants.

More than 36,000 of the 64,459 women who had $50 mammograms after a media campaign in 1987 completed a demographic and risk factor questionnaire. The screened women were young and well educated with high annual incomes. Only 32% had had mammograms before 1987. Most women reported that high cost and lack of referral for mammography by their physicians were their reasons for not being screened previously. Publicity promoting the project and the lower cost for mammography were the features of the project that attracted participants. Population-based telephone surveys before and after the project showed a change in attitudes about breast cancer screening. The model used for recruitment in this project can improve compliance with recommendations for regular mammographic screening if charges for screening are reduced. Additional efforts are needed to attract minorities and poor or elderly women to regular breast screening.

The Texas Breast Screening Project: Part I. Mammographic and clinical results.

The 1987 Texas Breast Screening Project was designed to educate women about the benefits and safety of mammographic screening. During the 2-week promotion, 109,339 women called toll-free telephone numbers to inquire about the program, and 64,459 (65%) of 99,650 eligible callers had $50 mammograms at 306 participating community radiology centers. Biopsies were obtained for 1,122 women (1.7% of those screened), and the ratio of benign to malignant biopsy results was 4.2:1. Among the women having biopsies, 214 cancers were found (3.3 cancers per 1,000 women screened). Forty-seven percent of the tumors were not palpable, 80% were smaller than 2 cm, and 72% were clinicopathologic stage 0 or I. These results show that women will respond to an invitation to attend mammographic screening, and that community radiology centers can detect large numbers of early, curable breast cancers.

Effects of a quantitative trait locus for muscle hypertrophy from Belgian Texel sheep on carcass conformation and muscularity.

A QTL for muscle hypertrophy has been identified in the Belgian Texel breed. A population of F2 and backcross lambs created from crosses of Belgian Texel rams with Romanov ewes was studied. Effects on carcass traits and muscle development of the Belgian Texel breed polygenes and Belgian Texel single QTL were compared. In both cases, carcass conformation and muscularity were improved. The Texel polygenic environment improved conformation mainly through changes in skeletal frame shape. Segments were shorter and bone weight lower. Muscles were more compact, shorter, and thicker. The single QTL affected muscle development. Thickness and weight of muscles were increased. Composition in myosin changed toward an increase of fast contractile type. The relative contribution of hind limb joint to carcass weight was increased. Differences in skeletal frame morphology among the three genotypes of the single QTL were small. Conformation scoring was mainly influenced by leg muscularity. Back and shoulder muscle development, which largely contributed to variability of muscularity, were less involved in the conformation scoring. Lastly, the QTL explains a small part of differences between these Belgian Texel and Romanov breeds for conformation or muscle development. A large part of genetic variability remains to be explored.