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  • Choline acetyltransferase  (4)
  • Drosophila  (4)
  • Physical Chemistry  (4)
  • respiratory sinus arrhythmia  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Mitochondrial DNA sequence divergence in theMelanogaster and oriental species subgroups ofDrosophila (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 156-162 
    Details
    ISSN: 1432-1432
    Keywords: Drosophila ; Mitochondrial DNA ; Nucleotide sequence ; Nonsynonymous substitutions ; Phylogeny ; A+T content
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nucleotide sequence of a segment of the mitochondrial DNA from threeDrosophila species (D. erecta, D. eugracilis, andD. takahashii), belonging to different subgroups of themelanogaster group has been determined. The segment encompasses three complete tRNA genes (tRNAtrp, tRNAcys, and tRNAtyr) and portions of two protein-coding genes: the subunit 2 of the NADH dehydrogenase (ND2) and the subunit 1 of the cytochrome oxidase (COI). Comparisons also involve homologous sequences already known for four otherDrosophila species of themelanogaster group. Length differences were confined in the intergenic region where a long stretch of AT repeats was observed in one of the species analyzed. The three tRNA genes exhibit very different evolutionary rates, the most slowly evolving one, tRNAtyr, is adjacent to the 5′ end of COI; tRNAs in similar positions have been previously shown to evolve slowly because they are probably involved in transcript processing. Although the rate of synonymous substitutions was very similar between ND2 and COI genes there were strong discrepancies between them in terms of the number of nonsynonymous substitutions. Differences have also been found in G+C content of the genes, which are likely to be linked to different selective pressures. There is a reduction in G+C content in the region where selective constraints are reduced. This suggests the existence of different levels of constraints along the sequenced segment. An overall analysis of the types of substitutions showed a decrease in A+T content during the course of evolution of the species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02193630
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  • 2
    Electronic Resource
    Electronic Resource
    Developmental regulatory elements in the 5′ flanking DNA of the Drosophila choline acetyltransferase gene (1993)
    Springer
    Development genes and evolution 202 (1993), S. 159-169 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Choline acetyltransferase ; cis-Regulatory element ; lacZ reporter gene ; Colinergic neuron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Choline acetyltransferase (ChAT, EC 2.3.1.6) catalyzes the production of the neurotransmitter acetylcholine, and is an essential factor for neurons to be cholinergic. We have analyzed regulation of the Drosophila ChAT gene during development by examining the β-galactosidase expression pattern in transformed lines carrying different lengths of 5′ flanking DNA fused to a lacZ reporter gene. The largest fragment tested, 7.4 kb, resulted in the most extensive expression pattern in embryonic and larval nervous system and likely reflects all the cis-regulatory elements necessary for ChAT expression. We also found that 5′ flanking DNA located between 3.3 kb and 1.2 kb is essential for the reporter gene expression in most of the segmentally arranged embryonic sensory neurons as well as other distinct cells in the CNS. The existence of negative regulatory elements was suggested by the observation that differentiating photoreceptor cells in eye imaginal discs showed the reporter gene expression in several 1.2 kb and 3.3 kb transformants but not in 7.4 kb transformants. Furthermore, we have fused the 5′ flanking DNA fragments to a wild type ChAT cDNA and used these constructs to transform Drosophila with a Cha mutant background. Surprisingly, even though different amounts of 5′ flanking DNA resulted in different spatial expression patterns, all of the positively expressing cDNA transformed lines were rescued from lethality. Our results suggest that developmental expression of the ChAT gene is regulated both positively and negatively by the combined action of several elements located in the 7.4 kb upstream region, and that the more distal 5′ flanking DNA is not necessary for embryonic survival and development to adult flies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00365306
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  • 3
    Electronic Resource
    Electronic Resource
    Developmental expression of choline acetyltransferase mRNA inDrosophila (1990)
    Springer
    Neurochemical research 15 (1990), S. 1089-1096 
    Details
    ISSN: 1573-6903
    Keywords: Choline acetyltransferase ; development ; mRNA ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have measured the steady state levels of choline acetyltransferase (ChAT, EC 2.3.1.6) mRNA during different developmental stages ofDrosophila melanogaster using a ChAT specific cRNA probe. ChAT mRNA was first detected approximately 6–7 h after oviposition, increased until the 1st–2nd larval instar, decreased into early pupal stages and increased again during late pupation, reaching a maximum in adults. Northern analysis showed a major RNA band with a Mr of 4.7 kilobases and Western analysis also showed a single major 75 kD protein band at all developmental stages. Our results support the hypothesis that a major point of regulation of ChAT expression may be at the transcriptional level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01101709
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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
    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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  • 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
    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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  • 8
    Electronic Resource
    Electronic Resource
    Short Communications. Biphenyl-3,4′-Dinitrene (1991)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 4 (1991), S. 459-462 
    Details
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Photolysis of biphenyl-3,4′ -diazide in a rigid glassy matrix at 77 K yields quintet state biphenyl-3,4′ -dinitrene with zero-field splitting parameters of |D/hc- = 0.153 cm-1 and |E/hc| = 0.019 cm-1 determined by electron spin resonance spectroscopic studies. Curie plot studies are consistent with assigning the quintet to be the ground state in this species. This finding confirms qualitative connectivity-based predictions for this general connectivity type of openshell system, and is in qualitative agreement with spectral INDO-CI computational predictions for both planar and twisted geometries of the dinitrene.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/poc.610040708
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  • 9
    Electronic Resource
    Electronic Resource
    Zero-field splitting versus interelectronic distance in triplet electron spin resonance spectra of localized dinitrenes (1993)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 6 (1993), S. 483-487 
    Details
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Triplet zero-field splitting parameters were obtained in 2-methyltetrahydrofuran glass at 77 K for phenylene-1,4-dinitrene (1), biphenyl-4,4′-dinitrene (2), (E)-1,2-bis(4′-nitrenophenyl)ethene (3), 1,4-bis(4′-nitrenophenyl)buta-1,3-diene (4) and 1,8-bis(4′-nitrenophenyl)octa-1,3,5,7-tetraene (5). The results were (1) |D/hc| = 0·169 cm-1 |E/hc| = 0·004 cm-1, (2) |D/hc| = 0·189 cm-1, |E/hc| = 0·00 cm-1, (3) |D/hc| = 0·122 cm-1, |E/hc| = 0·00 cm-1, (4) |D/hc| = 0·0865 cm-1, |E/hc| = 0·00 cm-1 and (5) |D/hc| = 0·0442 cm-1, |E/hc| = 0·00 cm-1. All these biradicals are ground-state singlets. Based on the observed decrease in triplet signal intensities as temperature decreases. The substantial magnitudes of |D/hc| for 3-5, despite the large distance between localized nitrene electrons, is much more than can be explained by a simple dipolar interaction between localized electrons, and is attributed at least partly to spin polarization effects on the π-electron clouds of these systems.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/poc.610060807
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  • 10
    Electronic Resource
    Electronic Resource
    Intramolecular exchange coupling of arylnitrenes by OXYGEN (1994)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 7 (1994), S. 495-502 
    Details
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A series of m,n′-diazidodiphenyl ethers (m ≤ n, m = 3,4; n = 3,4) was photolyzed at 77 K in frozen, glassy 2-methyltetrahydrofuran matrices to generate the corresponding diphenyl ether m,n′-dinitrenes for study by electron spin resonance (ESR) spectroscopy. 3,4′-Diazidodiphenyl ether gave an ESR spectrum dominated by a mononitrene peak with ∣D/hc∣ = 0·972 cm-1, and also showed a weak dinitrene quintet spectrum with ∣D/hc∣ = 0·162 cm-1 having ESR spectral intensity vs temperature dependence (Curie law) consistent with either a high-spin ground state or a very small singlet-quintet gap. Di(3-azidophenyl) ether gave a strong mononitrene peak with ∣D/hc∣ = 0·996 cm-1 and a quintet dinitrene ESR spectrum (∣D/hc∣ = 0·162 cm-1) which exhibited non-linear Curie law intensity behavior consistent with the quintet being a thermally populated excited state 40 cal mol-1 above a singlet ground state. Di(4-azidophenyl) ether gave a strong mononitrene peak with ∣D/hc∣ = 0·961 cm-1, but no observable spectrum related to a high-spin open-shell dinitrene. The results are consistent with oxygen being a weak exchange coupling linker in pi-conjugated open-shell molecules. The observed ground-state spin multiplicities are in accord with qualitative superexchange and connectivity models, despite any perturbations due to resonance effects between the oxygen linker and p-nitrene sites.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/poc.610070905
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