This contribution endeavours to show the substance of Machovec’s philo¬sophical thinking in the context of his time and the coordinates of his personal life. Tis we can best trace in the problems the seeking meaning in life. That is for Machovec a lifelong concern. He understands humans and their discovery of meaning in this world as a complex problem. Its core is a cultivated orientation of each individual in the world. As a “master of dialogue”, Machovec shows the possibilities of seeking self-determination in this way.
Interspecies differences in glycosidation potential in mammalian tissues represent a factor contributing to ambiguity when endobiotic and/or xenobiotic metabolic pathways are extrapolated from animals to man. Using the TLC/autoradiographic technique, we conducted an in vitro investigation involving mouse, rat, monkey, as well as human liver and kidney microsomes to evaluate their glycoconjugation potential towards 3H-labeled, purine-derived selective inhibitors of cyclin-dependent kinases such as olomoucine, bohemine, roscovitine, 6-(2-hydroxybenzyl)amino-2-(1-hydroxymethyl-2-methylpropyl)amino-9-isopropylpurine (compound A-4), and 6-(3-hydroxybenzyl)amino-2-[(1(R/S)-hydroxymethyl)propyl]amino-9-isopropylpurine (compound A-5) as aglycones. Principally, this study confirmed the aliphatic hydroxyl group of olomoucine-type inhibitors as a relatively suitable target for glucuronide, glucoside, xyloside, galactoside, and/or N-acetylaminoglucoside conjugation. Of the tissues examined, only the mouse microsomes were able to perform glucosidation and galactosidation reactions with the aglycones. On the other hand, monkey microsomes were superior to the mouse microsomes in a variety of glucuronide conjugates produced with compounds A-4 and A-5., K. Červenková, M. Belejová, Z. Chmela, M. Rypka, D. Riegrová, K. Michnová, K. Michalíková, I. Šúrová, A. Brejcha, J. Hanuš, B. Černý, K. Fuksová, L. Havlíček, J. Veselý., and Obsahuje bibliografii
The present study was aimed to investigate the mesenteric arteriovenous differences in blood glucose and lactate and plasma insulin in humans (n = 8) and rats (n=10). Arterial (abdominal aorta) and mesenteric vein blood glucose and lactate (enzymatic methods) and plasma insulin concentrations (radioimmunoassay) were measured in patients during abdominal surgery and in normal rats. Blood glucose levels were significantly (p<0.05) higher in the abdominal aorta than in the mesenteric vein in both rats (9.2±1.0 vs 7.5±0.8 mmol/1) and humans (10.4±2.9 vs 8.5±2.7 mmol/1). Blood lactate levels were higher (p<0.05) in the mesenteric vein in both rats (3.7±1.3 vs 2.8±0.9 mmol/1) and humans (0.7±0.23 vs 0.1 ±0.05 mmol/1). Plasma insulin concentrations were identical in the aorta or mesenteric vein in both rats (314.4± 162.0 vs 311.4±94.2 pmol/1) and humans (62.4±43.2 vs 61.8±48.0 pmol/1). In conclusion, both rat and human intestine retained a high proportion of arterially administered glucose and released lactate under the studied conditions.
Two procedures for eliciting premovement potentials were compared: (1) the estimation of a 3 s interval elapsed after a warning auditory signal, and (2) classical "self-pacing". Eleven healthy right-handed subjects participated in the experiment, EEG records from scalp electrodes placed at Cz, C3+ and C4 + were analyzed. It has been shown that both procedures induced similar premovement potentials except that in the first procedure the early component of the potential was longer. The time estimation itself induced a negative slow potential consisting of a rapid set-up and a subsequent plateau.
In humans, CD46 has been detected on the acrosomal membrane in sperm, in contrast to widespread surface expression on somatic cells where it plays a key role in the protection from complement attack. In rodents, CD46 is expressed solely on the acrosomal membrane of mature sperm and their immediate precursors, spermatids. A monoclonal antibody against the short consensus repeat (SCR1) ectodomain of CD46 blocks binding of human sperm to zona-free oocytes in vitro. However, CD46-knockout mice are fertile and have an accelerated spontaneous acrosome reaction. Wild-caught field mice (Apodemus) also exhibit a rapid acrosome reaction and CD46 is not expressed in Apodemus sperm. CD46 may, therefore, play a role in stabilization of the acrosomal membrane. Two other complement regulatory proteins, CD55 and CD59, are localized on the plasma membrane of mammalian sperm. In human sperm, CD55 and CD59 are expressed also on the inner acrosomal membrane. It remains to be clarified what is the role of CD46, CD55 and CD59 during fertilization and what are the advantages of not expressing CD46 in field mice sperm.
The linear relaxation (LR) was studied in isometric unfused tetanus (UT) of the human flexor digitorum sublimis muscle. With a decrease of the force level, the shoulder on the relaxation curve, as measured from the last stimulus, shifted to the right. The length of the linear portion itself weakly depended on activation level. When steady force changed from 100 to 40-50 % of the maximum, the slope of LR decreased only by 15±4 %. At smaller force levels the slope began to increase. LR can probably also be hidden in the twitch. With increased tetanus duration, LR becomes longer and slower at all force levels. LR was markedly diminished in contraction on the steep part of the exponential relaxation after a smooth tetanus. Its full recovery needed a train of 4-5 pulses (near 1 s) at the new stationary level. The form of the response to the additional pulse given during relaxation remained approximately constant during the most of LR portion and differed markedly before and after it. LR did not have direct relation to fatigue: in the first UT LR was always slower and longer than in subsequent ones.
Prediction of the final transferred fat volume is essential for the success of fat grafting, but remains elusive. Between 20 and 80 % of the initial transplanted volume can be creabsorbed. Although graft survival has many determinants, CD34+ progenitor cells from the vascular stroma of adipose tissue play a central role by promoting growth of blood vessels and adipocytes. We aimed to verify the hypothesis that a higher proportion of total CD34+ cells in the transplant is associated with better preservation of the graft volume. Human lipoaspirates from 16 patients were processed by centrifugation and two grafts per donor were subcutaneously injected into 32 nude mice in 1 ml volumes in the right upper flank area. The volume of each graft was measured using a preclinical MRI scanner immediately after grafting and at three months. The percentage of CD34+ cells in the graft before implantation was determined by flow cytometry. The final graft volume at three months after implantation directly correlated with the percentage of CD34+ cells in the grafted material (r = 0.637, P = 0.019). The minimum retention of the fat graft was 28 % and the maximum retention was 81 %, with an average of 54 %. Our study found that fat retention after fat transfer directly correlated with the fraction of CD34+ cells in the graft. The simple and fast determination of the CD34+ cell percentage on site can help predicting outcomes of fat transplantation. and Corresponding authors: Ondřej Měšťák, Luděk Šefc