Influence of cycloheximide on the lung

1975 ◽  
Vol 38 (4) ◽  
pp. 623-629 ◽  
Author(s):  
D. B. Gail ◽  
G. D. Massaro ◽  
D. Massaro
Keyword(s):  
Oxygen Consumption ◽  
Surface Density ◽  
Time Course ◽  
Lamellar Body ◽  
Lamellar Bodies ◽  
Cytoplasmic Area ◽  
The Right

We examined the time course of the influence of cycloheximide on descending pressure-volume curves of excised lungs and on protein and lecithin synthesis and oxygen consumption by lung slices. We also looked at the influence of cycloheximide on granular pneumocyte ultrastructure. Excised lungs from cycloheximide-treated animals are more compliant than controls. After ventilation with air, lungs from control and cycloheximide animals show increased retractive forces and a shift to the right of the deflation P-V curve. Incubation at 38 degrees C for 30 min reverses these changes in control lungs, but not in lungs from cycloheximide-treated rabbits. There is no change in liquid delfation P-V curves after cycloheximide. Cycloheximide causes an immediate decrease of 50% in incorporation of radioactive leucine into protein by lung slices. Incorporation of radioactive palmitate into lecithin and oxygen consumption are also decreased by 50% 6 h after cycloheximide. Lamellar bodies in granular pneumocytes are smaller after cycloheximide. Cycloheximide causes a significant increase in the surface density of the lamellar body envelope. Cytoplasmic area of granular pneumocytes is increased after cycloheximide.

scholarly journals A Time-Course Comparison of Skeletal Muscle Metabolomic Alterations in Walker-256 Tumour-Bearing Rats at Different Stages of Life

Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 404
Author(s):  
Gabriela de Matuoka e Chiocchetti ◽  
Leisa Lopes-Aguiar ◽  
Natália Angelo da Silva Miyaguti ◽  
Lais Rosa Viana ◽  
Carla de Moraes Salgado ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Time Course ◽  
Cancer Cachexia ◽  
Tumour Bearing ◽  
Walker 256 Tumour ◽  
Walker 256 ◽  
Muscle Changes ◽  
The Right ◽  
Biomarker Research ◽  
Host Metabolism

Cancer cachexia is a severe wasting condition that needs further study to find ways to minimise the effects of damage and poor prognosis. Skeletal muscle is the most impacted tissue in cancer cachexia; thus, elucidation of its metabolic alterations could provide a direct clue for biomarker research and be applied to detect this syndrome earlier. In addition, concerning the significant changes in the host metabolism across life, this study aimed to compare the metabolic muscle changes in cachectic tumour-bearing hosts at different ages. We performed 1H-NMR metabolomics in the gastrocnemius muscle in weanling and young adult Walker-256 tumour-bearing rats at different stages of tumour evolution (initial, intermediate, and advanced). Among the 49 metabolites identified, 24 were significantly affected throughout tumour evolution and 21 were significantly affected regarding animal age. The altered metabolites were mainly related to increased amino acid levels and changed energetic metabolism in the skeletal muscle, suggesting an expressive catabolic process and diverted energy production, especially in advanced tumour stages in both groups. Moreover, these changes were more severe in weanling hosts throughout tumour evolution, suggesting the distinct impact of cancer cachexia regarding the host’s age, highlighting the need to adopting the right animal age when studying cancer cachexia.

Time course of release of atrial natriuretic peptide in the anaesthetized dog

1986 ◽  
Vol 64 (7) ◽  
pp. 1017-1022 ◽  
Author(s):  
J. R. Ledsome ◽  
N. Wilson ◽  
A. J. Rankin ◽  
C. A. Courneya
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Time Course ◽  
Atrial Wall ◽  
Humoral Mechanism ◽  
Arterial Plasma ◽  
The Right ◽  
Atrial Receptors ◽  
Anaesthetized Dog ◽  
Atrial Natriuretic

In 12 chloralose anaesthetized dogs plasma concentration of immunoreactive atrial natriuretic peptide (IR-ANP) was measured using a radioimmunoassay. Plasma IR-ANP was 74 ± 4.8 pg/mL (mean ± SE) and increased by 39 ± 4.1 pg/mL when left atrial pressure was increased by 10 cm H2O during partial mitral obstruction. Observation of the time course of the changes in IR-ANP during atrial distension showed that IR-ANP was increased within 2 min of atrial distension and declined after atrial distension, with a half-time of 4.5 min. The time course of the changes in IR-ANP was unaffected by vagotomy or administration of atenolol. Maximum electrical stimulation of the right ansa subclavia failed to produce any change in IR-ANP. IR-ANP was higher in coronary sinus plasma than in femoral arterial plasma confirming that the heart was the source of the IR-ANP. The results support the hypothesis that IR-ANP is released from the heart by a direct effect of stretch of the atrial wall rather than by a neural or humoral mechanism involving a reflex from atrial receptors.

scholarly journals The Rapid Extraction of Gist—Early Neural Correlates of High-level Visual Processing

2012 ◽  
Vol 24 (2) ◽  
pp. 521-529 ◽  
Author(s):  
Frank Oppermann ◽  
Uwe Hassler ◽  
Jörg D. Jescheniak ◽  
Thomas Gruber
Keyword(s):  
Visual Processing ◽  
Time Course ◽  
Occipital Cortex ◽  
Stimulus Onset ◽  
Gamma Band ◽  
Oscillatory Activity ◽  
Rapid Extraction ◽  
The Right ◽  
High Level ◽  
Individual Objects

The human cognitive system is highly efficient in extracting information from our visual environment. This efficiency is based on acquired knowledge that guides our attention toward relevant events and promotes the recognition of individual objects as they appear in visual scenes. The experience-based representation of such knowledge contains not only information about the individual objects but also about relations between them, such as the typical context in which individual objects co-occur. The present EEG study aimed at exploring the availability of such relational knowledge in the time course of visual scene processing, using oscillatory evoked gamma-band responses as a neural correlate for a currently activated cortical stimulus representation. Participants decided whether two simultaneously presented objects were conceptually coherent (e.g., mouse–cheese) or not (e.g., crown–mushroom). We obtained increased evoked gamma-band responses for coherent scenes compared with incoherent scenes beginning as early as 70 msec after stimulus onset within a distributed cortical network, including the right temporal, the right frontal, and the bilateral occipital cortex. This finding provides empirical evidence for the functional importance of evoked oscillatory activity in high-level vision beyond the visual cortex and, thus, gives new insights into the functional relevance of neuronal interactions. It also indicates the very early availability of experience-based knowledge that might be regarded as a fundamental mechanism for the rapid extraction of the gist of a scene.

scholarly journals Time Course of Changes in Nitric Oxide Synthases Following Subarachnoid Hemorrhage in Primates

Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 359-360
Author(s):  
Robert L Macdonald ◽  
Bak Yamini ◽  
Bryce K Weir ◽  
Shigeki Ono
Keyword(s):  
Nitric Oxide ◽  
Subarachnoid Hemorrhage ◽  
Time Course ◽  
Cerebral Arteries ◽  
Inflammatory Cells ◽  
Inos Mrna ◽  
Messenger Ribonucleic Acid ◽  
Fold Reduction ◽  
Middle Cerebral Arteries ◽  
The Right

P114 Nitric oxide (NO) may be important in vasospasm following subarachnoid hemorrhage (SAH). We evaluated the time course of changes in 3 isoforms of NO synthase (NOS) after SAH in monkeys. Right SAH was created and vasospasm was assessed on angiograms obtained at baseline and after 3, 7 and 14 days. Animals were euthanized at these times (n = 4 - 6 per time) and the right and left (control) middle cerebral arteries were removed. Levels of nNOS, eNOS and iNOS messenger ribonucleic acid (mRNA) and protein were measured by reverse transcriptase polymerase chain reaction and Western blotting. Angiography showed a 45 ± 13% (mean ± s.d., p < 0.05) decrease in middle cerebral artery diameter 3 days, a 41 ± 23% (p< 0.05) decrease 7 days and an insignificant 6 ± 14% decrease 14 days after SAH. The RNA for eNOS was significantly reduced (1.7 ± 0.5-fold) 7 days after SAH. There was a significant, 1.7 ± 0.2-fold reduction in eNOS protein on days 3 and 7 after SAH that returned to normal by day 14. There were no significant changes in nNOS mRNA or protein at any time after SAH. There were no significant changes in iNOS mRNA whereas iNOS protein increased on days 3 and 7 (7 ± 9 and 2.7 ± 2.8-fold, respectively, p > 0.05) and significantly decreased (2.7 ± 1.1-fold, p < 0.05) on day 14. Immunohistochemistry localized eNOS to endothelium, nNOS to brain and perivascular adventitia of the middle cerebral arteries and iNOS to inflammatory cells in the subarachnoid space. These results show a correlation between decreased eNOS and increased iNOS during vasospasm, suggesting a complex role for changes in NO in vasospasm.

Outward currents in normal and hypertrophied feline ventricular myocytes

1989 ◽  
Vol 256 (5) ◽  
pp. H1450-H1461 ◽  
Author(s):  
R. B. Kleiman ◽  
S. R. Houser
Keyword(s):  
Time Course ◽  
Ventricular Myocytes ◽  
Pressure Overload ◽  
Negative Slope ◽  
Inward Rectification ◽  
Delayed Rectifier ◽  
Outward Currents ◽  
K Current ◽  
Prolongation Of Action Potential ◽  
The Right

The properties of the inward rectifier K current (IK1) and the delayed rectifier K current (IK) were studied in single feline myocytes isolated from the right ventricle of normal cats and cats with experimentally induced right ventricular hypertrophy (RVH). IK1 demonstrated time-dependent decay during hyperpolarizations and showed inward rectification with a prominent negative-slope region between -30 and -10 mV. Both IK1 and IK was carried primarily by K ions. The activation of IK during depolarizations followed a monoexponential time course, whereas the deactivation of IK tail currents was either mono- or biexponential depending on the repolarization potential. IK showed marked rectification at positive potentials. A comparison of these currents in normal and hypertrophy myocytes revealed that in RVH the magnitude of IK1 is increased, whereas the magnitude of IK is decreased. IK showed steeper rectification, had slower activation, and had more rapid deactivation in RVH. These abnormalities of the IK may contribute to the prolongation of action potential duration, which characterizes pressure-overload cardiac hypertrophy.

Metabolic control of Argyropelecus hemigymnus photophores: effects of glucose and pyruvate

1991 ◽  
Vol 69 (9) ◽  
pp. 2410-2413 ◽  
Author(s):  
J. Mallefet ◽  
F. Baguet
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Metabolic Control ◽  
Time Course ◽  
Light Emission ◽  
Mesopelagic Fish ◽  
Fresh Weight ◽  
Hypometabolic State ◽  
The Mean ◽  
Mean Time

Modifications in oxygen consumption and luminescence of isolated luminescent organs of the mesopelagic fish Argyropelecus hemigymnus following glucose and pyruvate administration were studied before and during light emission triggered by adrenaline. Isolated photophores (mean fresh weight 13.5 ± 0.9 mg) at rest, i.e., in the absence of light emission, in saline (20 °C) exhibit a respiration rate of 1.045 ± 0.082 (SE) nmol O2/min (n = 35). A significant decrease (p = 0.05) in oxygen consumption was observed after the addition of 5.5 mM glucose. Instead of the oxygen decrease usually observed as a result of control stimulations using adrenaline, photophores pretreated with glucose increased their oxygen uptake in response to adrenaline, and maximal light emission was reduced by 85% (p = 0.01). The addition of 5.5 mM pyruvate induced a significant transient increase (p = 0.05) in oxygen uptake of isolated photophores, though this treatment did not statistically modify the mean time course of oxygen consumption and light emission in response to adrenaline. The hypothesis of a hypometabolic state of the isolated photophores of A. hemigymnus during light emission is discussed.

scholarly journals Lamellar Body Phospholipid Content of Amniotic Fluid: A Possible Index of Fetal Lung Maturity

1979 ◽  
Vol 16 (1-6) ◽  
pp. 191-196 ◽  
Author(s):  
Coral G. Duck-Chong
Keyword(s):  
Amniotic Fluid ◽  
Individual Variation ◽  
Lamellar Body ◽  
Alveolar Epithelium ◽  
Fetal Lung ◽  
Phospholipid Content ◽  
Secretory Cells ◽  
Lamellar Bodies ◽  
Fetal Lung Maturity ◽  
Lung Maturity

Lamellar bodies, produced by secretory cells in the alveolar epithelium, are the major source of surfactant phospholipid. As the fetal lung matures, the membranous content of the lamellar bodies is secreted into the alveolar spaces and passes into the amniotic fluid, from which it can be isolated in a morphologically recognisable form. A method is described for the rapid isolation of a lamellar body fraction from amniotic fluid using a small air-driven clinical ultracentrifuge. The lamellar body phospholipid content of amniotic fluid increases towards the end of gestation, but the time of onset and the rate of this increase show wide individual variation. Preliminary results suggest that the lamellar body phospholipid content of amniotic fluid may be a useful index of fetal lung maturity.

On Respiration in the Dragonet Callionymus Lyra L

1968 ◽  
Vol 49 (3) ◽  
pp. 565-582
Author(s):  
G. M. HUGHES ◽  
SHUN-ICHI UMEZAWA
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Time Course ◽  
Water Pressure ◽  
Minute Volume ◽  
Individual Variations ◽  
Wide Range ◽  
The Relationship ◽  
Respiratory Rhythms ◽  
Normal Ventilation

1. The usefulness of a bottom-living fish, the dragonet (Callionymus lyra), in experiments on fish respiration is described. The position and nature of its opercular opening made it possible to determine directly the volume of water pumped over the gills and the PO2 of the mixed expired water. The normal ventilation volume for a 100 g. fish was about 30 c.c./min. 2. The relationship between cardiac and respiratory rhythms was investigated and showed a variety of ratios. The heart usually beats more than once during each respiratory cycle. Individual variations in the coupling between these rhythms was common and close couplings were observed in the absence of anaesthetic and at normal PO2s. 3. Changes in minute volume produced by altering the hydrostatic pressure across the respiratory system did not affect the heart rate. Percentage utilization fell at higher flow rates. Changes in flow per cm. of water pressure gradient was less with negative gradients than when the static pressure on the mouth side exceeded that in the opercular collecting chamber. 4. Oxygen consumption of the fish is directly related to the ambient PO2 over a wide range (30-120 mm. Hg). Sudden lowering of the PO2 in the inspired water leads to compensatory responses in which the minute volume is maintained or increased as a result of a rise in stroke volume and lowered respiratory frequency: there is also a marked bradycardia. During recovery the increased oxygen consumption of the fish resulted from a rise in utilization rather than a change in the respiratory rate or ventilation volume. 5. Analysis of the time course of the changes in heart rate and ventilation volume in experiments in which PO2 was changed supports the view that the receptors mediating bradycardia occur on the gills and respond directly to the change in PO2 rather than to the secondary increase in flow produced by the hypoxia.

Sudden Onset of Diplopia and a Skeletal Muscle Antibody

2021 ◽  
pp. 160-162
Author(s):  
John R. Mills
Keyword(s):  
Computed Tomography ◽  
Myasthenia Gravis ◽  
Patent Foramen Ovale ◽  
Time Course ◽  
Vision Loss ◽  
Sudden Onset ◽  
Foramen Ovale ◽  
Clinical Disorder ◽  
History Of ◽  
The Right

A 62-year-old man with a history of migraine came to the emergency department with sudden onset of horizontal diplopia and, subsequently, bilateral ptosis. He noted feeling unsteady when walking. He reported that the diplopia worsened throughout the day. He had a history of hepatitis C infection. He had some vision loss in his left eye, which was thought to relate to a retinopathy. He disclosed that he had a history of cold feet and had notably high arches. He had a pacemaker because of syncope attributed to sick sinus syndrome. Computed tomography angiography of the head and neck were ruled negative for intracranial stenosis, occlusions, or aneurysms. Computed tomography of the head indicated a tiny lacunar infarct in the right caudate head. Magnetic resonance imaging of the brain identified a tiny, periaqueductal, enhancing abnormality in the right midbrain that was thought to be likely ischemic, but there was some concern for a demyelinating or inflammatory lesion. Cerebrospinal fluid evaluation indicated an increased protein concentration. Serologic evaluation for myasthenia gravis striational antibodies were positive at a titer of 1:240. Serum protein studies indicated the presence of polyclonal hypergammaglobulinemia. Myasthenia gravis was effectively ruled out. Given the hyperacute time course, the patient’s clinical disorder was most probably explained by an ischemic stroke that affected the oculomotor nuclei regions causing ptosis and ophthalmoparesis. On follow-up, the patient was discovered to have a patent foramen ovale. Whether the patent foramen ovale was a contributing factor to the stroke is uncertain. The recurrence rate in this setting is thought to be low relative to other causes of stroke. Ultimately it was decided to not close the patent foramen ovale and to maintain the patient on clopidogrel and adult low-dose aspirin. The onset of diplopia is typically sudden, but this occurs exclusively with vascular pathologic processes. Diplopia that appears intermittently with diurnal variation suggests the possibility of a neuromuscular junction disease such as myasthenia gravis.

scholarly journals The right ventricular myocardial systolic-to-diastolic duration ratio in children after surgical repair of Tetralogy of Fallot

2020 ◽  
Vol 128 (6) ◽  
pp. 1677-1683
Author(s):  
Wei Hui ◽  
Cameron Slorach ◽  
Susan Iori ◽  
Andreea Dragulescu ◽  
Luc Mertens ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Cardiac Magnetic Resonance ◽  
Right Ventricular ◽  
Tetralogy Of Fallot ◽  
Surgical Repair ◽  
Peak Oxygen Consumption ◽  
Myocardial Performance ◽  
Repaired Tetralogy Of Fallot ◽  
2D Strain ◽  
The Right

This is the first study to assess right ventricular myocardial performance using the systolic-to-diastolic duration ratio derived from 2D strain. Seventy-six children with repaired Tetralogy of Fallot were evaluated. Echocardiographic data were correlated with cardiac magnetic resonance and peak oxygen consumption during exercise. The results show the right ventricular myocardial systolic-to-diastolic duration ratio incorporates systolic and diastolic performance, electromechanical dyssynchrony, and postsystolic shortening and is associated with exercise capacity in repaired Tetralogy of Fallot.

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