scholarly journals Measuring phenotypic flexibility by transcriptome time‐course analyses during challenge tests before and after energy restriction

2019 ◽  
Vol 33 (9) ◽  
pp. 10280-10290 ◽  
Author(s):  
Inge P. G. Bussel ◽  
Parastoo Fazelzadeh ◽  
Gary S. Frost ◽  
Milena Rundle ◽  
Lydia A. Afman
Keyword(s):  
Time Course ◽  
Energy Restriction ◽  
Phenotypic Flexibility ◽  
Before And After ◽  
Challenge Tests

Preliminary Evaluation of a Weibull Function for Fitting Slow-Component Eye Velocity over the Time Course of Caloric-Induced Nystagmus

1989 ◽  
Vol 32 (3) ◽  
pp. 681-687 ◽  
Author(s):  
C. Formby ◽  
B. Albritton ◽  
I. M. Rivera
Keyword(s):  
Time Course ◽  
Slow Component ◽  
Weibull Function ◽  
Preliminary Evaluation ◽  
Mathematical Function ◽  
Before And After ◽  
Best Fitting ◽  
Eye Velocity ◽  
Fitting Parameters ◽  
Weibull Equation

We describe preliminary attempts to fit a mathematical function to the slow-component eye velocity (SCV) over the time course of caloric-induced nystagmus. Initially, we consider a Weibull equation with three parameters. These parameters are estimated by a least-squares procedure to fit digitized SCV data. We present examples of SCV data and fitted curves to show how adjustments in the parameters of the model affect the fitted curve. The best fitting parameters are presented for curves fit to 120 warm caloric responses. The fitting parameters and the efficacy of the fitted curves are compared before and after the SCV data were smoothed to reduce response variability. We also consider a more flexible four-parameter Weibull equation that, for 98% of the smoothed caloric responses, yields fits that describe the data more precisely than a line through the mean. Finally, we consider advantages and problems in fitting the Weibull function to caloric data.

Preoperative and postoperative cognitive functioning in patients with frontal meningiomas

2003 ◽  
Vol 98 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Oliver Tucha ◽  
Christian Smely ◽  
Michael Preier ◽  
Georg Becker ◽  
Geraldine M. Paul ◽  
...  
Keyword(s):  
Executive Functions ◽  
Cognitive Functioning ◽  
Time Course ◽  
Lesion Size ◽  
Test Battery ◽  
Surgical Removal ◽  
Specific Information ◽  
Content Type ◽  
Before And After ◽  
Fine Print

Object. There is presently no specific information available concerning the nature and course of cognitive deficits caused by intracranial meningiomas. In this prospective study the authors examined the cognitive functioning of patients with frontal meningiomas. Methods. Fifty-four patients with frontal meningiomas were examined neuropsychologically before and after neurosurgery. The test battery consisted of standardized instruments including those assessing memory, attention, visuoconstructive abilities, and executive functions. The time period between pre-and postoperative assessment ranged from 4 to 9 months. The patients' performance was compared with the results in 54 healthy adults who were also assessed twice by using the same test battery in a period ranging from 4 to 9 months. In addition, the effect on cognition of meningioma lateralization, localization, lesion size, edema, brain compression, time course, and the occurrence of preoperative seizures was analyzed. Conclusions. Except in the case of working memory, comparisons of pre- and postoperative assessments of cognition revealed no differences in memory, visuoconstructive abilities, or executive functions, although a postoperative improvement in attentional functions was observed. The results of this study indicate that the surgical removal of frontal meningiomas does not impair patients' cognitive functioning. Furthermore, improvements in attentional functions may occur in these patients.

scholarly journals Analysis of the resistance mediated by several R-factors to Tetracycline and Minocycline

1972 ◽  
Vol 20 (2) ◽  
pp. 239-252 ◽  
Author(s):  
J. M. Robertson ◽  
E. C. R. Reeve
Keyword(s):  
Tetracycline Resistance ◽  
Klebsiella Aerogenes ◽  
R Factor ◽  
Before And After ◽  
Challenge Tests ◽  
Simple Growth ◽  
High Level ◽  
K 12 ◽  
R Factors ◽  
Level Group

SUMMARYThe resistance levels conferred by the T-determinants in four R-factors to Tetracycline and Minocycline in cells ofEscherichia coliK 12, before and after induction of maximum resistance by treatment with sub-inhibitory concentrations of the drugs, are measured by simple growth-and-challenge tests. The effect of a plasmid TKwhich confers tetracycline resistance on its hostKlebsiella aerogenesis tested in the same way. The five T-determinants fall into a high-level and a low-level group for resistance, the former giving 3- to 4-fold higher resistance in both induced and uninduced cells than the latter. The T-determinants all confer much lower resistance to Minocycline (a tetracycline molecule modified at the C-6 and C-7 positions) than to Tetracycline. The main cause of this difference is that cells carrying a T-determinant exclude Minocycline much less efficiently than Tetracycline, but in addition Minocycline is less effective than Tetracycline in inducing increased resistance. These results are discussed in the light of a model put forward to explain the inducible nature of R-factor resistance to the tetracyclines.

Metabolic responses to head-down suspension in hypophysectomized rats

1993 ◽  
Vol 75 (6) ◽  
pp. 2718-2726 ◽  
Author(s):  
C. R. Woodman ◽  
C. M. Tipton ◽  
J. Evans ◽  
J. K. Linderman ◽  
K. Gosselink ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Time Course ◽  
Citrate Synthase ◽  
O2 Consumption ◽  
Hindlimb Muscles ◽  
Impaired Ability ◽  
Norepinephrine Concentration ◽  
Hindlimb Muscle ◽  
Before And After ◽  
Hypophysectomized Rats

Rats exposed to head-down suspension (HDS) exhibit reductions in maximal O2 consumption (VO2max) and atrophy of select hindlimb muscles. This study tested the hypothesis that an endocrine-deficient rat exposed to HDS would not exhibit reductions in VO2max or hindlimb muscle mass. Hypophysectomized (HYPX) and sham-operated (SHAM) rats were tested for VO2max before and after 28 days of HDS or cage control (CC) conditions. No significant reductions in VO2max were observed in HYPX rats. In contrast, SHAM-HDS rats exhibited a significant reduction in absolute (-16%) and relative (-29%) measures of aerobic capacity. Time course experiments revealed a reduction in VO2max in SHAM-HDS rats within 7 days, suggesting that cardiovascular adjustments to HDS occurred in the 1st wk. HDS was associated with atrophy of the soleus (-42%) in SHAM rats, whereas HYPX rats exhibited atrophy of the soleus (-36%) and plantaris (-13%). SHAM-HDS rats had significantly lower (-38%) soleus citrate synthase activities per gram muscle mass than SHAM-CC, but no significant differences existed between HYPX-HDS and -CC rats. HDS rats had an impaired ability to thermoregulate, as indicated by significantly greater temperature increases per unit run time, compared with their CC counterparts. Pretreatment plasma epinephrine levels were significantly lower in HYPX than in SHAM rats. Norepinephrine concentration was similar for all groups except HYPX-HDS, in which it was significantly higher. HDS had no significant effect on thyroxine or triiodothyronine. SHAM-HDS rats had significantly lower concentrations of testosterone and growth hormone.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Cannabinoids in Exhaled Breath following Controlled Administration of Smoked Cannabis

2013 ◽  
Vol 59 (12) ◽  
pp. 1780-1789 ◽  
Author(s):  
Sarah K Himes ◽  
Karl B Scheidweiler ◽  
Olof Beck ◽  
David A Gorelick ◽  
Nathalie A Desrosiers ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Time Course ◽  
Matrix Effects ◽  
Solid Phase ◽  
Driving Under The Influence ◽  
Phase Extraction ◽  
Exhaled Breath ◽  
C Storage ◽  
Before And After ◽  
Occasional Smoker

BACKGROUND Δ9-Tetrahydrocannabinol (THC), 11-nor-9-carboxy-THC (THCCOOH), and cannabinol (CBN) were measured in breath following controlled cannabis smoking to characterize the time course and windows of detection of breath cannabinoids. METHODS Exhaled breath was collected from chronic (≥4 times per week) and occasional (<twice per week) smokers before and after smoking a 6.8% THC cigarette. Sample analysis included methanol extraction from breath pads, solid-phase extraction, and liquid chromatography–tandem mass spectrometry quantification. RESULTS THC was the major cannabinoid in breath; no sample contained THCCOOH and only 1 contained CBN. Among chronic smokers (n = 13), all breath samples were positive for THC at 0.89 h, 76.9% at 1.38 h, and 53.8% at 2.38 h, and only 1 sample was positive at 4.2 h after smoking. Among occasional smokers (n = 11), 90.9% of breath samples were THC-positive at 0.95 h and 63.6% at 1.49 h. One occasional smoker had no detectable THC. Analyte recovery from breath pads by methanolic extraction was 84.2%–97.4%. Limits of quantification were 50 pg/pad for THC and CBN and 100 pg/pad for THCCOOH. Solid-phase extraction efficiency was 46.6%–52.1% (THC) and 76.3%–83.8% (THCCOOH, CBN). Matrix effects were −34.6% to 12.3%. Cannabinoids fortified onto breath pads were stable (≤18.2% concentration change) for 8 h at room temperature and −20°C storage for 6 months. CONCLUSIONS Breath may offer an alternative matrix for identifying recent driving under the influence of cannabis, but currently sensitivity is limited to a short detection window (0.5–2 h).

Long-term facilitation alters transmitter releasing properties at the crayfish neuromuscular junction

1986 ◽  
Vol 55 (3) ◽  
pp. 484-498 ◽  
Author(s):  
J. M. Wojtowicz ◽  
H. L. Atwood
Keyword(s):  
Neuromuscular Junction ◽  
Synaptic Transmission ◽  
Time Course ◽  
Muscle Fibers ◽  
Low Frequencies ◽  
Before And After ◽  
Binomial Parameter ◽  
Small Muscle ◽  
Long Term Facilitation

Synaptic transmission at the neuromuscular junction of the excitatory axon supplying the crayfish opener muscle was examined before and after induction of long-term facilitation (LTF) by a 10-min period of stimulation at 20 Hz. Induction of LTF led to a period of enhanced synaptic transmission, which often persisted for many hours. The enhancement was entirely presynaptic in origin, since quantal unit size and time course were not altered, and quantal content of transmission (m) was increased. LTF was not associated with any persistent changes in action potential or presynaptic membrane potential recorded in the terminal region of the excitatory axon. The small muscle fibers of the walking-leg opener muscle were almost isopotential, and all quantal events could be recorded with an intracellular microelectrode. In addition, at low frequencies of stimulation, m was small. Thus it was possible to apply a binomial model of transmitter release to events recorded from individual muscle fibers and to calculate values for n (number of responding units involved in transmission) and p (probability of transmission for the population of responding units) before and after LTF. In the majority of preparations analyzed (6/10), amplitude histograms of evoked synaptic potentials could be described by a binomial distribution with a small n and moderately high p. LTF produced a significant increase in n, while p was slightly reduced. The results can be explained by a model in which the binomial parameter n represents the number of active synapses and parameter p the mean probability of release at a synapse. Provided that a pool of initially inactive synapses exists, one can postulate that LTF involves recruitment of synapses to the active state.

62 Time course of improvement in secretory unbalance of asymmetric dimethylarginine and nitric oxide productions in response to exercise training in middle-aged and older adults

2020 ◽  
Vol 41 (Supplement_1) ◽  
Author(s):  
S Fujie ◽  
N Hasegawa ◽  
K Sanada ◽  
T Hamaoka ◽  
S Maeda ◽  
...  
Keyword(s):  
Older Adults ◽  
Exercise Training ◽  
Arterial Stiffness ◽  
Aerobic Exercise ◽  
Time Course ◽  
Exercise Intervention ◽  
Training Group ◽  
Middle Aged ◽  
Plasma Adma ◽  
Before And After

Abstract Funding Acknowledgements Supported by Grants-in-Aid for Scientific Research (#17H02182, #16K13059, M. Iemitsu; #18J01024, S. Fujie) Introduction Aging is well known to elevate risks of cardiovascular diseases. As a mechanism of these increased risks with aging, a reduction of nitric oxide (NO) production via augmented secretion of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthesis is related. Habitual aerobic exercise has shown to improve secretory unbalance of endothelium-derived regulating factors with aging, such as increase in NO and decrease in ADMA, resulting in the reduction of arterial stiffness. However, the time course of improvement in secretory unbalance of NO and ADMA productions in response to exercise training in middle-aged and older adults remains unclear. Purpose This study aimed to determine the time course of changes in plasma nitrite/nitrate (NOx) and ADMA levels related to exercise-training effects of arterial stiffness in healthy middle-aged and older adults. Methods Thirty-two Japanese healthy middle-aged and older subjects (67 ± 1 years) were randomly divided into two groups: exercise intervention and sedentary controls. Subjects in the training group completed 8-week of aerobic exercise training (60-70% peak oxygen uptake [VO2peak] for 45 min, 3 days/week). We evaluated plasma NOx and ADMA concentrations and carotid-femoral pulse wave velocity (cfPWV) as an index of arterial stiffness, measured every 2 weeks for 8-week in the training group. Results cfPWV was gradually declined from baseline to 8-week and significantly decreased from baseline at weeks 6 (P < 0.05) and 8 (P < 0.01). Plasma NOx level was gradually elevated during exercise intervention and significantly increased from baseline at weeks 6 (P < 0.05) and 8 (P < 0.01). Interestingly, plasma ADMA level was significantly decreased at 8-week intervention (P < 0.05). Furthermore, the exercise training-induced reduction in plasma ADMA level was negatively correlated with the change in plasma NOx level before and after the 8-week (r = -0.483, P < 0.05). The exercise training-induced change in plasma ADMA concentration was positively correlated with training-induced change in cfPWV before and after the 8-week (r = 0.633, P < 0.01). Additionally, there was a negative correlation between the changes in plasma NOx level and cfPWV before and after the 8-week (r = -0.642, P < 0.05). Conclusions These results suggest that habitual aerobic exercise can normalize the secretory unbalance of NO and ADMA productions in 6 to 8 weeks, and these balance normalizations may be contributed to the reduction of arterial stiffness in the middle-aged and older adults.

Deep breath reversal and exponential return of methacholine-induced obstruction in asthmatic and nonasthmatic subjects

2004 ◽  
Vol 96 (1) ◽  
pp. 137-142 ◽  
Author(s):  
Andrew C. Jackson ◽  
Margaret M. Murphy ◽  
John Rassulo ◽  
Bartolome R. Celli ◽  
Roland H. Ingram
Keyword(s):  
Healthy Subjects ◽  
Time Course ◽  
Rapid Decrease ◽  
Airway Wall ◽  
Methacholine Challenge ◽  
Order Process ◽  
Deep Breath ◽  
First Order ◽  
Before And After ◽  
Complete Reversal

A deep breath (DB) during induced obstruction results in a transient reversal with a return to pre-DB levels in both asthmatic and nonasthmatic subjects. The time course of this transient recovery has been reported to be exponential by one group but linear by another group. In the present study, we estimated airway resistance (Raw) from measurements of respiratory system transfer impedance before and after a DB. Nine healthy subjects and nine asthmatic subjects were studied at their maximum response during a methacholine challenge. In all subjects, the DB resulted in a rapid decrease in Raw, which then returned to pre-DB levels. This recovery was well fit with a monoexponential function in both groups, and the time constant was significantly smaller in the asthmatic than the nonasthmatic subjects (11.6 ± 5.0 and 35.1 ± 15.9 s, respectively). Obstruction was completely reversed in the nonasthmatic subjects (pre- and postchallenge mean Raw immediately after the DB were 2.03 ± 0.66 and 2.06 ± 0.68 cmH2O·l-1·s, respectively), whereas in the asthmatic subjects complete reversal did not occur (2.29 ± 0.78 and 4.84 ± 2.64 cmH2O·l-1·s, respectively). Raw after the DB returned to postchallenge, pre-DB values in the nonasthmatic subjects (3.78 ± 1.56 and 3.97 ± 1.63 cmH2O·l-1·s, respectively), whereas in the asthmatic subjects it was higher but not significantly so (9.19 ± 4.95 and 7.14 ± 3.56 cmH2O·l-1·s, respectively). The monoexponential recovery suggests a first-order process such as airway wall-parenchymal tissue interdependence or renewed constriction of airway smooth muscle.

Does baseline airway caliber affect measurements of airway responsiveness to histamine

1993 ◽  
Vol 74 (6) ◽  
pp. 3034-3039 ◽  
Author(s):  
O. P. Twentyman ◽  
S. V. Hood ◽  
S. T. Holgate
Keyword(s):  
Time Course ◽  
Geometric Mean ◽  
Forced Expiratory Volume ◽  
Airway Responsiveness ◽  
Bronchial Responsiveness ◽  
Subsequent Response ◽  
Airway Caliber ◽  
Before And After ◽  
Airway Response ◽  
Considerable Controversy

Considerable controversy exists over the influence of baseline airway caliber on indexes of bronchial responsiveness in asthma. To directly investigate this, we used inhaled methacholine to alter baseline airway caliber to determine whether this altered the airway response to subsequent bronchoprovocation with inhaled histamine. Seventeen stable asthmatic subjects were studied; their median age was 22 yr, baseline forced expiratory volume in 1 s (FEV1) was 101.5 +/- 3.7% (SE) predicted, and geometric mean provocative concentration of inhaled methacholine causing a 20% fall in FEV1 (PC20) was 0.87 mg/ml. Initially the time course of bronchoconstriction to inhaled methacholine was determined. Subsequently the airway response to inhaled histamine administered as a single concentration was determined, both before and after reductions in baseline FEV1 by saline or methacholine of 0, 15, 25, and 35%, on 4 separate days. Altering baseline airway caliber had no effect on the subsequent response of the airways to inhaled histamine when calculated as percent fall from the new baseline. The power of the study to detect an effect of altering baseline FEV1 on the measured PC20 histamine of 0.5 doubling dilutions was > 55%, and the power to detect an effect of 1.0 doubling dilutions was > 98%.

Inhibition of gastric mechanoreceptor discharge by cholecystokinin in the rat

1995 ◽  
Vol 268 (2) ◽  
pp. G355-G360 ◽  
Author(s):  
D. Grundy ◽  
V. Bagaev ◽  
K. Hillsley
Keyword(s):  
Indirect Effects ◽  
Time Course ◽  
Positive Response ◽  
Pressure Response ◽  
Gastric Distension ◽  
Afferent Fibers ◽  
Before And After ◽  
Afferent Discharge ◽  
Vagal Afferent

The aim of the present study was to investigate electrophysiologically the effect of systemic cholecystokinin (CCK) on the discharge of vagal gastric mechanoreceptors. Twenty-two single vagal afferent fibers were selected for the investigation of responses to intravenous CCK octapeptide (CCK-8) on the basis of a positive response to gastric distension. Resting discharge in these afferent fibers was 1.3 +/- 0.3 impulses.s-1 and increased to 9.2 +/- 0.9 impulses.s-1 during distension (P < 0.0001), CCK (20-100 pmol iv) caused a gastric relaxation of 2.1 +/- 0.2 cmH2O and inhibition of phasic motility. The discharge of 20/22 of vagal tension receptors closely followed the magnitude and time course of the fall in pressure. Mean discharge before and after CCK (50 pmol) was 7 +/- 0.9 and 3.9 +/- 0.8 impulses.s-1, respectively (P < 0.001, n = 22). Both the pressure response and the concomitant changes in afferent discharge were abolished by L-364,718 (1.2 mg/kg iv). Only two afferent units failed to show a decrease in firing following CCK (50 pmol), and at 500 pmol the discharge of these units was augmented. In conclusion, CCK (50 pmol) has predominantly indirect effects on gastric mechanoreceptors, which decrease their firing in association with gastric relaxation.

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