Publications by authors named "Krizkova M"

Article Synopsis
  • Cystathionine β-synthase (CBS)-deficient homocystinuria (HCU) is a genetic disorder affecting sulfur amino acid metabolism, leading to various health complications and underscoring the need for better understanding of its biological processes.
  • In a study involving a transgenic mouse model (I278T), researchers found significant metabolic imbalances, altered liver proteome, and changes in sphingolipid metabolism, although mitochondrial function appeared normal.
  • A methionine-restricted diet (MRD) was shown to improve metabolic balance and reduce liver proteome disruptions in I278T mice, suggesting potential therapeutic benefits for HCU.
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Background: In animals, dietary sulfur amino acid restriction (SAAR) improves metabolic health, possibly mediated by altering sulfur amino acid metabolism and enhanced anti-obesogenic processes in adipose tissue.

Aim: To assess the effects of SAAR over time on the plasma and urine SAA-related metabolites (sulfurome) in humans with overweight and obesity, and explore whether such changes were associated with body weight, body fat and adipose tissue gene expression.

Methods: Fifty-nine subjects were randomly allocated to SAAR (∼2 g SAA, n = 31) or a control diet (∼5.

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Article Synopsis
  • Regulation of hydrogen sulfide (HS) homeostasis in humans is not well understood, prompting a study of patients with rare enzyme deficiencies related to HS synthesis and catabolism.
  • Analysis of sulfur compounds in these patients revealed unexpected results, such as increased bioavailable sulfide levels in those with cystathionine β-synthase (CBS) deficiency, suggesting compensatory mechanisms at play.
  • The study highlights the complexity of HS regulation, showing that various genetic defects can lead to altered levels of sulfur compounds, underscoring the need for a thorough understanding of HS homeostasis in metabolic disorders.
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Increased plasma total cysteine (tCys) has been associated with obesity and metabolic syndrome in human and some animal studies but the underlying mechanisms remain unclear. In this study, we aimed at evaluating the effects of high cysteine diet administered to SHR-CRP transgenic rats, a model of metabolic syndrome and inflammation. SHR-CRP rats were fed either standard (3.

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Background And Purpose: Homocystinurias are rare genetic defects characterized by altered fluxes of sulfur compounds including homocysteine and cysteine. We explored whether the severely perturbed sulfur amino acid metabolism in patients with homocystinurias affects the metabolism of hydrogen sulfide.

Experimental Approach: We studied 10 treated patients with a block in the conversion of homocysteine to cysteine due to cystathionine β-synthase deficiency (CBSD) and six treated patients with remethylation defects (RMD) and an enhanced flux of sulfur metabolites via transsulfuration.

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Aims: The transsulfuration pathway enzymes cystathionine beta-synthase (CBS) and cystathionine gamma-lyase are thought to be the major source of hydrogen sulfide (HS). In this study, we assessed the role of CBS in HS biogenesis.

Results: We show that despite discouraging enzyme kinetics of alternative HS-producing reactions utilizing cysteine compared with the canonical condensation of serine and homocysteine, our simulations of substrate competitions at biologically relevant conditions suggest that cysteine is able to partially compete with serine on CBS, thus leading to generation of appreciable amounts of HS.

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The study examines the influence of vestibular and leg proprioceptive cues on the maintenance of the body vertical in human stance. Vestibular body orientation cues were changed by applying bipolar currents to both mastoid bones (cosine-bell wave form of 3.3 s duration, 1 mA current intensity).

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In order to understand proprioceptive and vestibular contributions to human stance posture, the effect of electrical vestibular stimulation on body lean induced by leg muscle vibration was investigated. The magnitudes and directions of postural responses were registered as changes in the center of foot pressure (COP) with a force platform. Vestibular stimulation consisted of 1 mA, binaural, bipolar galvanic current and proprioceptive input from tibialis anterior or soleus muscles was altered vibratory stimulation.

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The influence of monopolar binaural galvanic stimulation of the vestibular system was studied on body sway. Subjects, with eyes closed, were standing on a hard support or on foam rubber. Their body sway was registered on a force platform at intervals of 50 s.

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The influence of additional visual feedback (VF) on stance control was studied under conditions of changed afferent information from the foot sole and ankle joint due to different support surfaces. The changes of body sway amplitudes were analyzed and their frequency spectrum was established. The effect of visual feedback on the amplitude and frequency characteristics of human stance was manifested as: a) a decrease of the mean amplitude of body sway during visual feedback, corresponding to the decrease of power spectrum density (PSD) of stabilograms in the frequency range below 0.

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In 30 subjects (16 men and 14 women) stabilometry was used to investigate the stability of posture with closed eyes and different positions of the head (backward, forward, right and left turn). Cervical spine mobility of the subjects studied was determined by vertebrogenic examination. The maximum backward extension of the head was found to reduce most markedly posture stability.

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Postural adjustments due to the fast forward right arm elevation, performed during sinusoidal induced body oscillations in the phase of platform-induced dorsal, as well as plantar flexion of the foot were studied. Start times of the changes in the cyclic way of the center-of-gravity position (SG) and right ankle goniogram (GG) as well as the EMG onsets of the right soleus (S), anterior tibial (AT) and femoral biceps (FB) muscles relative to the ipsilateral anterior deltoid muscle (AD) EMG onset were measured. The EMG onset of FB muscle was found to occur significantly before the EMG onset of the AD muscle during plantar flexion series, wherever during dorsal flexion series the EMG onset of the AT muscle was significantly before the AD muscle EMG onset.

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The authors present physiological ranges of values of seven parameters of stabilometric examinations of the upright posture in man. In order to make the examination effective, the authors suggested and tested three situations which make it possible to characterize the activity of the visual, vestibular and proprioceptive feedback in the process of maintenance of the upright posture. For measuring the supporting forces during the upright posture the authors used a stabilometer with automatic compensation of the body weight.

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The stability of upright posture was studied by the method of stabilometry in 16 healthy subjects. The efficacy of involving visual, vestibular and proprioceptive afferentation in maintaining posture was examined in four test situations. A direct correlation of stabilometric parameters was established at posture on soft surface and at galvanic stimulation of the vestibular analyzer.

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