Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study examines the involvement of acidosis in stress ulceration in rat stomachs. Cold restraint stress for 2 hr did not affect the blood lactate level; however, it produced respiratory acidosis, as reflected by the depressed respiratory rate which was associated with increased CO2 tension and a lowered blood pH. Severe hemorrhagic ulceration was found in the glandular mucosa. The effects of stress on blood pH and the stomach were reversed by IV infusion of NaHCO3. Infusion of HCl IV decreased the blood pH and HCO-3 level and produced gastric ulceration. It is concluded that respiratory acidosis could be involved in stress ulceration. The metabolic acidosis evoked by HCl also induced gastric damage, but the effect was much less.
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PMID:Does acidosis contribute to stress-induced ulceration in rat stomachs? 255 22

The distribution of cyclic guanosine 3',5' monophosphate (cGMP) producing cells in various organs of the rat were studied immunocytochemically using antibodies raised against formaldehyde-fixed cGMP. Sodium nitroprusside (SNP), a direct activator of guanylate cyclase and vasodilator, was used to enhance cGMP levels. In order to reach all organs optimally, whole body perfusion was performed using a modified Krebs-Ringer buffer at 37 degrees C, aerated with 5% CO2/95% O2, also containing isobutyl methyl xanthine (IBMX); a phosphodiesterase inhibitor. After 15-min pre-perfusion, SNP was added to the perfusate, followed by fast fixation with ice-cold 4% paraformaldehyde-phosphate buffer. After vehicle perfusion, only the retina showed cGMP immunoreactivity in the photoreceptor and ganglion layer, while other organs lacked cGMP immunoreactivity. After 15-min perfusion with SNP (10 microM), enhanced cGMP immunostaining was seen in smooth muscles of the aorta, amacrine-like cells in the retina, glomeruli of the kidney cortex, blood vessels in the dura mater, as well as cells in the pineal and in the median eminence. The results indicate that the distribution and the reactivity of cGMP producing cells, situated outside the blood brain barrier, can be studied by immunocytochemistry after pharmacological manipulations of the intact tissue with a nitrovasodilator using whole body perfusion.
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PMID:cGMP immunocytochemistry in aorta, kidney, retina and brain tissues of the rat after perfusion with nitroprusside. 255 68

Twenty patients with panic attacks and ten controls were given a standardised interview about thoughts occurring during times of anxiety or panic attacks. The interviewer was blind to the subject's diagnosis. The 20 panic patients underwent a psychophysiological test battery which included a cold pressor test, mental arithmetic task, and 5.5% CO2 inhalation. More patients than controls reported thoughts centered on fears of losing control and shame when anxious. Panic patients rated their thoughts as stronger and clearer than did controls and they had more difficulty excluding them from their minds. A feeling of anxiety preceded anxious thoughts in patients. This suggests that 'faulty cognitions' are not the initial event in a panic attack, although anxious thoughts may exacerbate or maintain them. Significant correlations were found between the intensity of anxiety-related thoughts in anticipation of mental arithmetic and changes in diastolic blood pressure and heart rate during mental arithmetic.
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PMID:Cognitive aspects of panic attacks. Content, course and relationship to laboratory stressors. 260 37

The experimental objective was to determine whether moderate to severe hypoxemia increases skeletal muscle sympathetic nervous activity (MSNA) in resting humans without increasing venous plasma concentrations of norepinephrine (NE) and epinephrine (E). In nine healthy subjects (20-34 yr), we measured MSNA (peroneal nerve), venous plasma levels of NE and E, arterial blood pressure, heart rate, and end-tidal O2 and CO2 before (control) and during breathing of 1) 12% O2 for 20 min, 2) 10% O2 for 20 min, and 3) 8% O2 for 10 min--in random order. MSNA increased above control in five, six, and all nine subjects during 12, 10, and 8% O2, respectively (P less than 0.01), but only after delays of 12 (12% O2) and 4 min (8 and 10% O2). MSNA (total activity) rose 83 +/- 20, 260 +/- 146, and 298 +/- 109% (SE) above control by the final minute of breathing 12, 10, and 8% O2, respectively. NE did not rise above control at any level of hypoxemia; E rose slightly (P less than 0.05) at one time only with both 10 and 8% O2. Individual changes in MSNA during hypoxemia were unrelated to elevations in heart rate or decrements in blood pressure and end-tidal CO2--neither of which always fell. We conclude that in contrast to some other sympathoexcitatory stimuli such as exercise or cold stress, moderate to severe hypoxemia increases leg MSNA without raising plasma NE in resting humans.
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PMID:Hypoxemia raises muscle sympathetic activity but not norepinephrine in resting humans. 273 64

The carbon dioxide (CO2) laser as a surgical tool for the difficult cosmetic problem of rhinophyma permits unprecedented refinement in treatment. Previously described conventional techniques have included the cold knife and the dermabrader. With these methods, hemostasis must be obtained with electrocautery, which if used extensively makes fine sculpting difficult. Seven patients with rhinophyma were treated with the CO2 laser at the Lahey Clinic from 1982 to 1987. We used a laser handpiece with a variable spot size. With this technique, we found the laser to be an excellent cutting tool while simultaneously providing superior hemostasis. In the followup period of up to 4.5 years, the cosmetic results have been excellent. Thus, the CO2 laser has become our treatment of choice for the management of patients with rhinophyma.
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PMID:Management of rhinophyma with carbon dioxide laser: Lahey Clinic experience. 297 46

The TSH-responsive adenylate cyclase system was studied using porcine thyroid cells in a primary monolayer culture. Isolated porcine thyroid cells treated with collagenase were inoculated into 96 wells at the density of 5 X 10(4) viable cells/0.25 ml Ham F-12 containing 10% fetal bovine serum and cultured for 4 days in a humidified atmosphere with 5% CO2. Adenylate cyclase activities in the cells treated or non-treated with protein synthesis inhibitor were assayed in Hanks/20 mM Hepes buffer (pH 7.4) containing 1% BSA, 1 mM IBMX and various stimulants at 37 degrees C for 30 or 60 min. The reaction was stopped by adding ice-cold TCA, and cAMP content in the extract was measured by radioimmunoassay after treatment with water-saturated ether. The cultured thyroid cells had an adenylate cyclase system responsive to TSH, cholera toxin and forskolin. TSH (50 mU/ml) stimulated the activity about eight fold over the basal activity. Cholera toxin (1 microgram/ml) and forskolin (100 microM), however, were much stronger activators of the adenylate cyclase system. In the cells pretreated with cyclo-heximide (5 micrograms/ml) up to 24 hours, cAMP formation by TSH was potentiated 200 approximately 170% compared to that in non-treated cells, suggesting a suppression of an inhibitory mechanism dependent upon new protein synthesis. In contrast, forskolin (100 microM)-stimulation was greatly reduced to 30% of the control after 24-hour treatment. Cholera toxin (1 microgram/ml)-stimulation was significantly lessened or slightly reduced by the treatment. Although the ability of forskolin to act synergistically with TSH or cholera toxin was observed in non-treated cells, it was clearly unaffected and demonstrated in the cells treated with protein synthesis inhibitor. The mechanism(s) and site(s) of forskolin action still remain unclear. However, these observations are compatible with a two-site model of forskolin action. The direct activating site of forskolin appears to reside in a protein which is closely associated with the catalytic unit of adenylate cyclase system and has a relatively shorter half-life than other components of the system. The potential action of forskolin may reside in a more stable complex of an activated stimulatory guanine nucleotide binding component and catalytic unit of the adenylate cyclase system. Based on these results, it is likely that the primary monolayer culture of porcine thyroid cells is a good model to investigate the adenylate cyclase system in the thyroid, and that forskolin may potentiate the TSH-mediated stimulation of adenylate cyclase.
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PMID:[Adenylate cyclase system responsive to thyroid stimulating hormone (TSH) of porcine thyroid cells in primary monolayer cultures. Potential effect of forskolin on TSH-mediated adenylate cyclase stimulation]. 303 Aug 31

The Na+ and K+ gradients of HeLa cells approach that of the medium during removal from a substrate with trypsin, but then recover during the next 15 min. The recovery is blocked by ouabain or the cold, but is unaffected by bumetanide. The effect is also obtained in cells which have no intercellular connexions, and in cells whose interior is made acid with CO2. Removal of cells with EDTA, pronase E and dispase has similar effects. It does not occur, or is greatly reduced, in cells already rounded up. Substances of molecular weight up to 5000 (e.g. inulin) also cross the cell membrane during this phase. We think that the effect is due to a transient increase in leakiness of the cell during rounding up, possibly due to the detachment of the 'feet' holding the cells onto the substrate. The transient increase in permeability of these cells may be a valuable method of introducing large molecules into them.
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PMID:Transient changes in permeability in HeLa and L cells during detachment from a substrate. 303 99

Freezing and thawing of leaves of herbaceous plants leads to damage when the freezing temperature falls below a certain tolerance limit, which depends on the plant species and state of acclimation. Such damage is expressed as an irreversible inhibition of photosynthesis observed after thawing. In frost-damaged leaves the capacity of photosynthetic reactions of the thylakoid membranes is impaired. Particularly, the water-oxidation system, photosystems II and I are inhibited. However, it appears that CO2 assimilation is more readily affected by freezing stress than the activity of the thylakoids. The inhibition of CO2 fixation seen in initial stages of damage seems to be independent of thylakoid inactivation. This can be shown by chlorophyll fluorescence analysis made simultaneously with measurement of CO2 assimilation. Fluorescence emission by leaves is strongly influenced by carbon assimilation activity, namely via the redox state of the photosystem II electron acceptor QA (QA-dependent quenching) and via energization of the thylakoid membranes depending on the transthylakoid proton gradient (energy-dependent quenching). Resolution of these components of fluorescence changes provides insight into alterations of the CO2 fixing capacity of the chloroplasts and properties of the thylakoids. The effects of freezing and thawing were studied in detail with isolated mesophyll protoplasts prepared from both non-hardened and cold-acclimated plants of Valerianella locusta L. Freezing damage was characterized by various parameters such as plasma membrane integrity, photosynthetic CO2 assimilation, chlorophyll fluorescence emission and activities of thylakoids isolated from the protoplasts. All tests indicated a substantially increased frost tolerance of protoplasts obtained from cold-acclimated as compared to non-hardened leaves. CO2 assimilation and related fluorescence changes were the most freezing-sensitive parameters in both types of protoplasts. Inactivation of CO2 assimilation was correlated neither to the disintegration of the plasma membrane nor to inactivation of the thylakoids. Experimental data indicate that freeze-thaw treatment affected the light-regulated enzymes of the carbon reduction cycle, such as fructose-1,6-bisphosphatase, sedoheptulose-1,7-bisphosphatase and ribulose-1,5-bisphosphate carboxylase. Inhibition of light-activation of these enzymes may be based on altered properties of the chloroplast envelope.
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PMID:Effects of freezing on plant mesophyll cells. 307 62

Four series of experiments have been performed in normal subjects to determine whether face immersion gives rise to a reduction in ventilatory drive. Such a response might be advantageous, like the cardiovascular components of the 'diving response', in prolonging breath-hold diving. In the first series, ventilatory drive was measured indirectly as the maximal voluntary breath-holding time, starting each breath-hold at the same alveolar partial pressures and at the same lung volume. When the face was immersed in cold water, breath-holding times were increased by 14%. The breaking point occurred at a higher alveolar PCO2 and the rate of rise of PCO2 was not affected. Control immersions in warm water had no effect. In the second and third series, subjects lay prone and breathed either air or 5% CO2 through a valve in the bottom of a bowl. Minute ventilation was measured before, during and after 5 min of face immersion in cold water. Transient hypoventilations of 13% and 10% respectively were seen, accompanied by small rises in alveolar PCO2. In control experiments, immersion of the forearm in cold water produced the opposite responses. In the fourth series, a cold wet pack was applied to the face during moderate steady-state exercise. A small irregular hypoventilation was seen, but not in control experiments when a warm pack was applied. Face temperatures fell by about 10 degrees C in these experiments. No material changes were found in the temperatures of the inspired air or of the aural canal. It is concluded that face immersion in cold water causes a modest reduction in ventilatory drive in man. This appears to be a component of the 'diving response'.
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PMID:Ventilatory drive during face immersion in man. 308 97

The impulse activity of afferent fibers was studied in n. ethmoidalis. While the room air was being sucked in through the nasal cavity to choanes, marked excitation of cold receptors of the nasal cavity walls occurred. In the air current from the choanes to the nostrils, the activity of the receptors was depressed. Insufflation through the nasal cavity of the mixtures of CO2 (1, 3, 6%) with air also depressed the activity of cold receptors. The degree of the depression depended on the concentration of CO2. The cold receptors of nasal cavity like the lung stretch receptors, have the features of chemoreceptors. Their activity is depressed with physiological concentrations of CO2 in the air.
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PMID:[Suppressive effect of carbon dioxide on excitation of the cold receptors of the nasal cavity of the cat]. 308 95


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