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  • 1
    Electronic Resource
    Electronic Resource
    Cold stress response in Archaea (2000)
    Springer
    Extremophiles 4 (2000), S. 321-331 
    Details
    ISSN: 1433-4909
    Keywords: Key words Cold shock ; Low-temperature adaptation ; Psychrophile ; Adaptive mechanisms ; Antarctic Archaea ; Gene expression ; Protein structure ; Review
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We live on a cold planet where more than 80% of the biosphere is permanently below 5°C, and yet comparatively little is known about the genetics and physiology of the microorganisms inhabiting these environments. Based on molecular probe and sequencing studies, it is clear that Archaea are numerically abundant in diverse low-temperature environments throughout the globe. In addition, non-low-temperature-adapted Archaea are commonly exposed to sudden decreases in temperature, as are other microorganisms, animals, and plants. Considering their ubiquity in nature, it is perhaps surprising to find that there is such a lack of knowledge regarding low-temperature adaptation mechanisms in Archaea, particularly in comparison to what is known about archaeal thermophiles and hyperthermophiles and responses to heat shock. This review covers what is presently known about adaptation to cold shock and growth at low temperature, with a particular focus on Antarctic Archaea. The review highlights the similarities and differences that exist between Archaea and Bacteria and eukaryotes, and addresses the potentially important role that protein synthesis plays in adaptation to the cold. By reviewing the present state of the field, a number of important areas for future research are identified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007920070001
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  • 2
    Electronic Resource
    Electronic Resource
    Induction of cardiac angiotensin I-converting enzyme with dietary NaCl-loading in genetically hypertensive and normotensive rats (1995)
    Springer
    Journal of molecular medicine 73 (1995), S. 243-248 
    Details
    ISSN: 1432-1440
    Keywords: Angiotensin I-converting enzyme ; Gene expression ; Sodium chloride ; Heart ; Inbred rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have recently shown that the angiotensin I converting enzyme (ACE) gene is linked to NaCl-loaded blood pressure in the stroke-prone spontaneously hypertensive rat (SHRSP), and that high-NaCl loading selectively stimulates ACE in the aorta of SHRSP but not in normotensive Wistar-Kyoto (WKY) rats. We therefore investigated the relationship between cardiac ACE and the development of hypertension and left ventricular hypertrophy in response to normal- and high-NaCl diet in these rats. ACE mRNA and ACE activity were measured in left ventricular tissue after completion of hemodynamic characterization of the animals. While SHRSP rats increased blood pressure (P〈0.0001) and heart rate (P〈0.005) in response to high NaCl, blood pressure remained unchanged in WKY. Similarly, relative left ventricular weight increased only in SHRSP after high NaCl (P〈0.002). A significant two- to threefold increase of cardiac ACE mRNA and fourfold stimulation of ACE enzyme activity in response to high NaCl was found in both WKY and SHRSP rats (P〈0.005). The induction of ACE gene expression was significantly more pronounced in SHRSP compared to WKY (P〈0.02), whereas no significant strain differences in left ventricular ACE activity were found after either normal- or high-NaCl diet. Thus, arterial blood pressure and left ventricular weight remained unchanged in the WKY rats despite the activation of left ventricular ACE activity after high-NaCl exposure. These results demonstrate that left ventricular ACE activity is equally upregulated in response to high-NaCl in the normotensive and hypertensive strain, independently from the development of hypertension. We conclude that the pretranslational induction of left ventricular ACE with high-NaCl loading may be important both for the regulation of cardiac angiotensins and kinins and for local therapeutic ACE inhibition in the heart during high-salt status.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00189924
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  • 3
    Electronic Resource
    Electronic Resource
    Plasma-membrane H+-ATPase gene expression is regulated by NaCl in cells of the halophyte Atriplex nummularia L. (1993)
    Springer
    Planta 190 (1993), S. 433-438 
    Details
    ISSN: 1432-2048
    Keywords: Atriplex ; Gene expression ; NaCl regulation ; Halophyte ; Plasma-membrane H+-ATPase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An Atriplex nummularia L. cDNA probe encoding the partial sequence of an isoform of the plasma-membrane H+ -ATPase was isolated, and used to characterize the NaCl regulation of mRNA accumulation in cultured cells of this halophyte. The peptide (447 amino acids) translated from the open reading frame has the highest sequence homology to the Nicotiana plumbaginifolia plasma-membrane H+-ATPase isoform pma4 (greater than 80% identity) and detected a transcript of approximately 3.7 kb on Northern blots of both total and poly(A)+ RNA. The mRNA levels were comparable in unadapted cells, adapted cells (cells adapted to and growing in 342 mM NaCl) and deadapted cells (cells previously adapted to 342 mM NaCl that are now growing without salt). Increased mRNA abundance was detected in deadapted cells within 24 h after exposure to NaCl but not in unadapted cells with similar salt treatments. The NaCl up-regulation of message abundance in deadapted cells was subject to developmental control. Analogous to those reported for glycophytes, the plasma-membrane H+-ATPase are encoded by a multigene family in the halophyte.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224780
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  • 4
    Electronic Resource
    Electronic Resource
    Relationship Between Changes in EMG and Respiratory Sinus Arrhythmia in a Study of Relaxation Therapy for Asthma (1997)
    Springer
    Applied psychophysiology and biofeedback 22 (1997), S. 183-191 
    Details
    ISSN: 1573-3270
    Keywords: asthma ; respiratory sinus arrhythmia ; relaxation ; vagal tone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This paper reports the relationships among changes in cardiovagal activity, surface EMG, and measures of pulmonary function in a study of relaxation therapy for asthma. Changes in FEV 1 /FVC were negatively correlated with those in cardiac interbeat interval, consistent with the hypothesis that relaxation-induced changes in airway function are mediated autonomically, with increased vagal tone and/or decreased sympathetic arousal producing bronchoconstriction. Contrary to Kotses's theory of a vagal-trigeminal reflex as mediator for relaxation-induced improvement in asthma, decreases in pulmonary function occurred during relaxation sessions, accompanied by increases in cardiovagal activity, and within-session changes in frontal EMG in the first session of training were positively associated with changes in a measure of pulmonary function (FEV1/FVC). However, consistent with this hypothesis, first-session frontalis EMG changes were positively associated with changes in respiratory sinus arrhythmia, and last-session changes in cardiac interbeat interval were positively associated with changes in FEV1/FVC. The results suggest that the immediate effects of generalized relaxation instruction can be associated with a parasympathetic rebound, which, in turn, may induce countertherapeutic changes in asthma. However, the effects of specific facial muscle relaxation remain uncelar.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026263826106
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  • 5
    Electronic Resource
    Electronic Resource
    Resonant Frequency Biofeedback Training to Increase Cardiac Variability: Rationale and Manual for Training (2000)
    Springer
    Applied psychophysiology and biofeedback 25 (2000), S. 177-191 
    Details
    ISSN: 1573-3270
    Keywords: respiratory sinus arrhythmia ; cardiac variability ; baroreflexes ; biofeedback ; homeostasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Heart rate and blood pressure, as well as other physiological systems, among healthy people, show a complex pattern of variability, characterized by multifrequency oscillations. There is evidence that these oscillations reflect the activity of homeostatic reflexes. Biofeedback training to increase the amplitude of respiratory sinus arrhythmia (RSA) maximally increases the amplitude of heart rate oscillations only at approximately 0.1 Hz. To perform this task people slow their breathing to this rate to a point where resonance occurs between respiratory-induced oscillations (RSA) and oscillations that naturally occur at this rate, probably triggered in part by baroreflex activity. We hypothesize that this type of biofeedback exercises the baroreflexes, and renders them more efficient. A manual is presented for carrying out this method. Supporting data are provided in Lehrer, Smetankin, and Potapova (2000) in this issue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009554825745
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  • 6
    Electronic Resource
    Electronic Resource
    Cardiac rhythm effects of .125-Hz paced breathing through a resistive load: Implications for paced breathing therapy and the polyvagal theory (1996)
    Springer
    Applied psychophysiology and biofeedback 21 (1996), S. 131-147 
    Details
    ISSN: 1573-3270
    Keywords: paced breathing ; respiratory sinus arrhythmia ; vagal tone ; flow-resistive breathing ; homeostasis ; parasympathetic system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study examined the psychophysiological effects of slow-paced breathing while subjects breathed through external respiratory resistive loads. Twenty-four normal volunteers completed four 5-min trials of paced breathing (.125 Hz) through an inspiratory resistive wire mesh screen (0 to 25 cm H2O/L/s). Each trial was followed by a 5-min rest trial. There was evidence for hyperventilation and/or fatigue during paced breathing. Also, respiratory sinus arrhythmia (RSA) was elevated in the first minute of paced breathing, and then declined toward baseline. Heart period decreased during paced breathing trials, and fell significantly below baseline during rest periods. These data suggest decreased vagus nerve activity and/or sympathetic activation, following an initial increase in parasympathetic activity during paced breathing. They are not consistent with the use of .125-Hz paced breathing as a relaxation technique, particularly during respiratory resistive stress. Finally, although RSA and average heart period changed synchronouslywithin paced breathing and rest conditions, they diverged incomparisons between pacing and rest. This dissociation suggests that different mechanisms mediate these two cardiac parameters. These data are consistent with Porges' theory that vagal influences on tonic heart rate are mediated by the combined effect of vagal projections from both the nucleus ambiguus and the dorsal motor nucleus, while RSA is mediated only through the nucleus ambiguus alone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02284692
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  • 7
    Electronic Resource
    Electronic Resource
    Emotionally Triggered Asthma: A Review of Research Literature and Some Hypotheses for Self-Regulation Therapies (1998)
    Springer
    Applied psychophysiology and biofeedback 23 (1998), S. 13-41 
    Details
    ISSN: 1573-3270
    Keywords: asthma ; biofeedback ; repressive coping ; respiratory sinus arrhythmia ; EMG biofeedback ; psychophysics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Asthma is a common disease whose morbidity and mortality are rapidly increasing. Panic disorder is common in asthma. Panic, other negative emotions, and a passive coping orientation may affect asthma by producing hyperventilation, increased general autonomic lability, a specific pattern of autonomic arousal that may cause bronchoconstriction, and/or detrimental effects on health care behaviors. Generalized panic is a risk factor for increased asthma morbidity. A repressive coping style also appears to be a risk factor for asthma morbidity because it is accompanied by an impaired ability to perceive symptoms, a necessary prerequisite for taking appropriate remediation. Several self-regulation strategies are hypothesized to be useful adjuncts to asthma treatment. Preliminary research has been done on relaxation therapy, EMG biofeedback, biofeedback for improved sensitivity in perceiving respiratory sensations, and biofeedback training for increasing respiratory sinus arrhythmia. It is hypothesized that finger temperature biofeedback also may be a promising treatment method, and that relaxation-oriented methods will have their greatest effect among asthmatics who experience panic symptoms, while improved perceptual sensitivity will be helpful both for patients who panic and those with repressive coping styles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022170028979
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    Paper (German National Licenses)
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