Histological characteristics and functional properties of red and white parts of m. semitendinosus of slaughter pigs

A unique muscle of pigs (Sus scrofa domesticus) is m. semitendinosus, which contains the “red” (dark) part located mainly in the depth of the leg cut and the “white” (light) part located in the close proximity to the subcutaneous fat layer. Differences in the characteristics of its “red” and “white” parts can exert a significant effect on quality and economic indicators of meat products. The aim of this research was to study histological features of the microstructure and technological properties of muscle tissue from different parts of m. semitendinosus, obtained from slaughter pigs of Russian production. M. semitendinosus was excised from chilled porcine carcasses (N=20) 24 hours after slaughter in the process of deboning. Histological examination showed that the dark part of the muscle was characterized by a higher package density of fibers, higher number of capillaries and higher sarcomere length. On the contrary, the light part was characterized by a higher diameter of muscle fibers. Analysis of muscle fiber types showed that the proportion of type I, intermediate and type IIb fibers was higher by 9.3, 5.2 and 4.1%, respectively, in the dark part. Significant differences between the dark and light parts of m. semitendinosus were revealed in terms of the number and size of giant fibers: the light part was characterized by a larger number (by more than 5 times) of giant fibers with the fibers of a larger size (almost by 11%). The samples of minced meat from the dark and light parts showed significant (р<0.05) differences in the mean values of lightness, redness and yellowness (L*, a* and b*) by 6.00, 4.68 and 3.01 units, respectively, in raw samples, and by 6.53, 2.99 and 1.81, respectively, after curing with the nitrite mixture and cooking (р<0.05). The dark part of m. semitendinosus had higher pH values (р<0.05) both for raw and cooked samples. The consistency of the samples from the light part was less elastic, looser and more crumbly than that in the samples produced from the dark part of m. semitendinosus, which was confirmed by the structural-mechanical investigations. Therefore, this study showed significant differences between the dark and light parts of m. semitendinosus by microstructural and functional-technological characteristics. Significant variability by muscle fiber diameter, which was observed in the light part of this muscle, apparently should be taken into account in breeding work and quality assessment of pork from slaughter animals

Postslaughter state of muscle tissue of pigs depending on the duration of pre-slaughter fasting

Changes in the muscle tissue microstructure lead to changes in meat quality. One of the causes of the myopathy development is animal stress. Pigs experience the strongest stress during pre-slaughter holding. The study of the postmortem meat structure depending on fasting time is a topical task. The objects of the research were samples of m. L. dorsi obtained after slaughter from pigs that differed in fasting time: 4 (group 1), 8 (group 2), 10 (group 3), 16 (group 4) and 18 (group 5) hours (N = 20, n = 4). Investigation of the microstructure and morphometric measurements were carried out on preparations stained with hematoxylin and eosin. Myopathic changes in muscle tissue were assessed using a semi-quantitative method developed earlier. All studied samples were characterized by the uniform condition of muscle tissue. Statistically significant differences between individual groups were observed regarding the number and area of giant fibers, sarcomere length, diameter of muscle fibers and proportion of muscle fibers, which diameter was lower or higher by 1/3 than the mean fiber diameter. An increase in the pre-slaughter holding time reduced the number and area of giant fibers (r = –0.8437 and –0.5796, respectively), as well as the diameter of “normal” fibers (r = –0.5337), which positively influenced pork quality. Groups 1, 2 and 3 were characterized by the presence of signs of moderate and pronounced myopathy. Only one carcass with pronounced myopathic signs was revealed in each of groups 4 and 5. In group 4, one carcass did not have signs of myopathy. Pre-slaughter holding during 4, 8 and 10 hours led to deterioration of pork quality. The recommended fasting time is 16 hours

DETECTION OF AUTOANTIBODIES RECOGNIZING CANCERRETINA ANTIGEN RECOVERIN IN BLOOD OF PATIENTS WITH NON-INVASIVE FOLLICULAR THYROID NEOPLASMS WITH PAPILLARY-LIKE NUCLEAR FEATURES (NIFTP)

Autoantibodies recognizing the cancer-retina autoantigen called recoverin (RCVRN-AutoAb) may serve as a highly specific biomarker of cancer-associated retinopathy. However, they may also be found in some cancer patients without clinical evidence of retinopathy. In the present study, dot-ELISA and Western blot assays were used to demonstrate the presence of circulating RCVRN-AutoAb in 4/7 (57%) of patients with recently recognized pathological entity, non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP); other thyroid tumors represented by follicular adenomas, and classical and follicular variants of papillary thyroid carcinomas, demonstrated low frequencies of RCVRN-AutoAb (0/15, 1/20 (5%) and 1/15 (7%), respectively), with no significant differences from healthy individuals (0/15). Our data implicate the circulating RCVRN-AutoAb as a potential biomarker of NIFTP capable of discrimination of this novel pathological entity from other thyroid tumors

Composition of organic matter from black shales drilled in the Cape Verde Basin in DSDP Hole 41-367

Results of geochemical studies of organic matter in black shales from the Cape Verde Basin are reported. Based on these results, in combination with data of petrographic analysis, conclusions are made about sapropelic nature of their organic matter and low degree of its coalification. It corresponds to the proto-catagenetic substage of sedimentary rocks. Black shales of the Cape Verde Basin are classified as potential oil source strata

Composition of sediments and cores from DSDP Legs 54 and 61-63

The monograph gives results of studies of sediments and rocks collected from D/S Glomar Challenger in the Pacific Ocean. These studies have been based on the lithological facial analysis applied for the first time for identificating genesis of ocean sediments. These results include new ideas on formation of the Earth's sedimentary cover and can be used for constructing regional and global schemes of ocean paleogeography, reconstructing some structures, correlating sedimentation on continents and in oceans, estimating perspectives of oil- and gas-bearing deposits and ore formation. The monograph also gives the first petrographic classification of organic matter in black shales