Disease relevance of Carbon

• Uncontrolled studies in over 800 patients have confirmed that CO2 likely has a very low renal toxicity [1].
• However, these studies also showed clearly that renal ischemia can occur due to a "vapor lock" phenomenon if the kidney is positioned vertically above the injection site, and recurrent injections are given without time for absorption of the arterially delivered CO2 boluses [1].
• At the University of Florida, CO2 is the radiologic contrast agent of choice in patients with renal insufficiency, especially those with diabetes mellitus, and in those with pre-existing allergy to iodinated contrast agents [1].
• BACKGROUND: Pneumoperitoneum with room temperature carbon dioxide (CO2) has been shown to decrease core temperature and urine output [2].
• One death each occurred in moderate hemorrhage groups, both near the end of CO2 pneumoperitoneum [3].

Psychiatry related information on Carbon

• Carbon dioxide (CO2) inhalation induces acute anxiety and panic attacks in patients with Panic Disorder (PD) [4].
• One hundred twenty-three patients with PD with or without agoraphobia who were hyperreactive to CO2 were randomly assigned to treatment groups with imipramine, clomipramine, paroxetine, sertraline, or fluvoxamine [4].
• The inhalation of carbon dioxide (CO2) may, therefore, provide a good paradigm for exploring the pathways by which stress can lead to increased susceptibility to ill-health through physiological and psychological stress reactivity [5].
• It was found that in rats a gradient of retrograde amnesia for a passive avoidance response could be established when carbon dioxide (CO2) was used as the amnesic agent [6].
• The time course of amnesia for a one-trial passive avoidance response after treatment with carbon dioxide (CO2) was studied [7].

High impact information on Carbon

• It has generally been assumed that during photosynthesis, oxygen in CO2 reaches isotopic equilibrium with oxygen in 18O-enriched water in leaves [8].
• We show, however, large differences in the activity of carbonic anhydrase (which catalyzes CO2 hydration and 18O exchange in leaves) among major plant groups that cause variations in the extent of 18O equilibrium (theta(eq)) [8].
• After 3 years of CO2 fumigation, trees were twice as likely to be reproductively mature and produced three times as many cones and seeds as trees at ambient CO2 concentration [9].
• Carbon dioxide (CO2) has been increasing in atmospheric concentration since the Industrial Revolution. A decreasing number of stomata on leaves of land plants still provides the only morphological evidence that this man-made increase has already affected the biosphere [10].
• The current rate of CO2 responsiveness in individual long-lived species cannot be accurately determined from field studies or by controlled-environment experiments [10].

Chemical compound and disease context of Carbon

• The intramuscular injection of meperidine (1 mg./kg.) alone causes significant respiratory depression, and doxapram (2 mg./kg.) alone causes significant respiratory stimulation, as evidenced by their ability to shift the carbon dioxide (CO2) response curve to the right and left, respectively [11].
• Twelve cases of phenytoin hyperplasia removed surgically by the CO2 laser are presented; hence a laser gingivectomy [12].
• Pseudomonas MA3 was isolated from activated sludge on the basis of its capacity to use dodecyldimethylamine as a sole carbon (C) and energy source [13].
• BACKGROUND: Nodular amyloidosis is a rare cutaneous disorder for which many treatments have been described, including carbon dioxide (CO2) laser vaporization [14].
• Thus, our results suggest that during the majority of dives, O2 and CO2 levels in lesser scaup ducks are managed through changes in diving behavior without any major cardiovascular adjustments, but below a threshold PaO2, a bradycardia is evoked to conserve the remaining oxygen for hypoxia sensitive tissues [15].

Biological context of Carbon

• The gas carbon dioxide (CO2) plays a critical role in microbial and mammalian respiration, photosynthesis in algae and plants, chemoreception in insects, and even global warming . However, how CO2 is transported, sensed, and metabolized by microorganisms is largely not understood [16].
• The CAN2 gene encoding beta-carbonic anhydrase in C. neoformans was found to be essential for growth in environmental ambient conditions but dispensable for in vivo proliferation and virulence at the high CO2 levels in the host [16].
• OBJECTIVE: Previous studies have suggested that manipulations in patient instructions before inhalation of carbon dioxide (CO2) may blunt its anxiogenic effects [17].
• On the other hand, deficiency in CYP21 expression is known to cause excessive production of adrenal C19 steroids, suggesting that CYP21 could play a role in adrenarche [18].
• METHOD: NO concentrations measured by a chemiluminescence analyser (Dasibi Environmental Corporation) and carbon dioxide (CO2) measured by a Morgan capnograph were analysed in single exhalations from total lung capacity in healthy volunteers (mean age 35.9 years) [19].

Anatomical context of Carbon

• Studies of the effects of carbon dioxide (CO2) lasers on dental enamel have demonstrated that surface changes can be produced at low fluences (< 10 J/cm2) if wavelengths are used which are efficiently absorbed by the hard tissues [20].
• Very small vessels, equivalent to third-order branches of the renal artery, can be imaged satisfactorily with CO2 [1].
• Experimental studies in dogs, whose renal arteries have been injected repeatedly with very large doses of CO2, demonstrate only transient changes in renal blood flow and no endothelial cell damage [1].
• CONCLUSION: Ablation of the entire epidermis and papillary dermis with either pulsed or scanned CO2 lasers appears generally ineffective in treating recalcitrant psoriatic plaques, although the clearing seen in two patients suggests potentially successful future research directions [21].
• Because the air in the esophagus has very low levels of CO2, the use of capnometers may help prevent unrecognized esophageal intubation in prehospital and emergency department settings [22].

Associations of Carbon with other chemical compounds

• The can2 mutation restored early mating events in high CO2 but not later steps (fruiting body formation, sporulation), indicating a major role for carbonic anhydrase and CO2/HCO3- in this developmental cascade leading to the production of infectious spores [16].
• The effects of short treatments (7 days) with paroxetine and with reboxetine on the reactivity to inhalations of 35% carbon dioxide (CO2)/65% oxygen (O2) were compared in 28 patients with Panic Disorder who had positive responses to 35% CO2 inhalations [23].
• After 30 min of infusion, approximately 10% of the total 13C in brain extracts appeared in GABA, primarily (greater than 80%) at the amino carbon (C4), indicating that the GABA detected is labeled through pyruvate carboxylase [24].
• BZ agonists (alprazolam, 0.01-1.0 mg/kg; lorazepam, 0.3-10.0 mg/kg; quazepam, 1.0-5.6 mg/kg) decreased VT and VE during both 5% CO2 and air inhalation [25].
• RESULTS: A single inhalation of CO2 increased blood pressure, noradrenaline, salivary alpha amylase and psychosomatic symptoms, but decreased heart rate at both testing sessions [5].

Gene context of Carbon

• Similar to the rat at P5, mice at P6 are unable to sustain an increase in CO2 induced respiratory frequency and GAD65 contributes to this fall off [26].
• GAD65-/- animals at P6 showed a sustained increase in respiratory rate for the five mins exposure to CO2 [26].
• Open-top chambers were used to expose young trembling aspen (Populus tremuloides) and sugar maple (Acer saccharum) trees to ambient (36 Pa) and elevated (56 Pa) atmospheric CO2 [27].
• For instance, increasing the aliphatic character of the acyl side chain resulted in an increase in the upfield shift of the acyl bearing aromatic ring carbon, (C2), in the incorporated probe molecule as compared to the unincorporated probe molecule [28].
• The purpose of this study was to investigate the effect of breathing 5% CO2 on presyncopal tolerance to lower body negative pressure (LBNP) [29].

Analytical, diagnostic and therapeutic context of Carbon

• Therefore, we have explored the use of carbon dioxide (CO2) as an alternative angiographic contrast agent used in combination with digital subtraction angiography [1].
• In this study, scanning electron microscopy (SEM) was used to characterize the wavelength dependence of surface changes in dental enamel after exposure to an extensive range of CO2 laser conditions [20].
• Intraperitoneal insufflation with CO2 for diagnostic laparoscopy may be hazardous in acute hypovolemic trauma patients [3].
• METHODS: Patients were randomized to undergo laparoscopic cholecystectomy with a CO2 pneumoperitoneum warmed to either body temperature (n = 15) or room temperature (n = 15) [30].
• In patients with normal perfusion and ventilation, end-tidal CO2 measurements closely reflect alveolar PCO2 [22].

References