Leptin is produced by white adipose tissue and other cell types and is involved in both short- and long-term appetite control. Here we studied effects of star vation on serum, pituitary and hypothalamic levels of leptin during 72 h period. Each of the starved groups was sacrificed simultaneously with the group of ad libitum fed animals. The progression of the discrete starvation response phases was monitored by testing the blood glucose, free fatty acid, urea and corticosterone levels. Starvation caused biphasic increase in corticosterone and free fatty acid levels, and significant but transient decrease in urea and glucose levels. Starvation also abolished diurnal rhythm of changes in leptin concentrations in serum and hypothalamic and pituitary tissues. Only 6 h starving period was sufficient to lock serum leptin at low levels, whereas 12 h were needed to silence leptin production/secretion in hypothalamus for the whole examined period. In contrast, leptin production by pituitary tissues of starved animals required 24 h to reach minimum, followed by full recovery by the end of starvation period. These resu lts indicate the tissue specific pattern of leptin release and suggest that the locally produced leptin could activate its receptor in pituitary cells independently of serum levels of this hormone., P. Vujovic ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Chronology of three consecutive mitotic events in human preimplantation embryos was examined by time-lapse imaging. In zygotes producing well-formed and pregnancy-yielding expanded blastocysts, uniform time-patterning of cleavage clusters (c) and interphases (i) was revealed: i2=11±1, i3=15±1, i4=23±1 h / c2=15±5, c3=40±10, c4=55±15 min. Oppositely, shortened or prolonged durations of one or more cell cycles were strongly predictive of poor implantation and development. Furthermore, trichotomic mitosis was discovered in 17 % of cases - zygotes cleaved into 3 blastomeres and 2-cell embryos into 5-6 cells (instead of normal 2 and 4). During conventional clinical assessment, such embryos are indistinguishable from normal, often considered just-in-course of the next cell cycle. Only detailed time-lapse monitoring paced at 10-minute intervals had proven all these embryos to be absolutely unviable, even in rare cases when they reduced their hypercellularity to normal cell counts via cell-cell fusion. Overall, we demonstrate that timelapse embryo cleavage rating (ECR) as a standalone diagnostic procedure allows for effective identification of viable early embryos with 90 % specificity, while elimination of good-looking but unviable embryos can be assumed with a specificity of 100 %. Thus, making this non-invasive and contactless approach worth of addition to routine embryo screening in clinical IVF programs., D. Hlinka ... [et al.]., and Obsahuje seznam literatury
Myostatin (MSTN), an important negative regulator of skeletal muscle, plays an important role in skeletal muscle health. In previous study, we found that the expression of MSTN was different during skeletal muscle injury repair. Therefore, we explored the expression changes of MSTN at different time points during skeletal muscle injury repair after eccentric exercise. In addition, MSTN is regulated by follistatin (FST) and decorin (DCN) in vivo, so our study examined the time-specific changes of FST, DCN and MSTN in the circulation and skeletal muscle during skeletal muscle injury repair after eccentric exercise, and to explore the reasons for the changes of MSTN in the process of exercise-induced muscle injury repair, to provide a basis for promoting muscle injury repair. The rats performed one-time eccentric exercise. Blood and skeletal muscle were collected at the corresponding time points, respectively immediate after exercise (D0), one day (D1), two days (D2), three days (D3), seven days (W1) and fourteen days (W2) after exercise (n=8). The levels of MSTN, FST, DCN in serum and mRNA and protein expression in muscle were detected. MSTN changes in the blood and changes in DCN and FST showed the opposite trend, except immediately after exercise. The change trends of mRNA and protein of gastrocnemius DCN and MSTN are inconsistent, there is post-transcriptional regulation of MSTN and DCN in gastrocnemius. Acute eccentric exercise might stimulate the secretion of DCN and FST into the circulation and inhibit MSTN. MSTN may be regulated by FST and DCN after acute eccentric exercise.
Between 1997 and 2001, the birth dates of free living and captive Alpine musk deer were examined to determine fawning patterns, and discuss potential influencing factors. In the wild, parturition shows strong seasonality, and occurred in three months from May to July, most of the births (75%) occurring within a 27 day period. Environmental seasonality, including the climate and forage availability, plays the major role in determining the timing of births in wild musk deer. Similarly, fawning in captivity shows constancy between years and seasonality, although with later initiation and a longer season than in the wild, influenced by an environmental seasonality of relatively lower intensity. More detailed differences in fawning patterns were observed in different rows of enclosures, resulting from differences in human care, and intensified by the social interaction among individuals within a row of enclosures. Although the fawning pattern is not strongly related to age of the captives, an individual’s reproductive history seemed to influence fawning timing and synchrony, and the birth date is not strongly related to the survival of the newborn.
The impact of blasting operations is accompanied by both positive and negative after-effects. Vibrations, activated by explosion, help to disintegrate the rocks representing a positive effect on one hand and a negative effect on the other and they endanger the surrounding buildings and other properties. If the vibrations are large enough, then the ambient objects could be damaged or destroyed. The negative effects depend on their range and strength. Vibration intensity of seismic waves is generally proportional to the weight of the explosive used. Recently, negative effects of the blasting operations and quantification of the seismic safety have been highly actual and stand for a challenging problem. The article highlights the results of the blasting operation monitoring in some quarry in Slovakia., Julián Kondela and Blažej Pandula., and Obsahuje bibliografické odkazy