Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present study, changes in frequency and amplitude of the rhythmic variations (vasomotion) in blood flow in the intact cerebral circulation of the rat were investigated using laser-Doppler flowmetry (LDF) during stepwise decrease in mean arterial blood pressure (MABP) and hyper- and hypocapnia. Experiments were performed on 12 adult Sprague-Dawley rats of either sex, anesthetized with alpha-chloralose. The rat's head was fixed on a stereotaxic frame and a small hole was made in the parietal bone but the dura and a thin inner bone layer were kept intact. The microvascular blood flow of the parietal cortex on the right or on both sides was continuously recorded by the laser-Doppler flowmeter (Periflux PF2B, Perimed, Stockholm, Sweden). The cerebral circulation of the rat exhibited vasomotion in control conditions with a frequency of 8-10 cycles per minute (cpm) and an amplitude of 5-10% of the cerebral blood flow (CBF). No significant changes in CBF could be detected when the MABP was above 60 mmHg, but it decreased significantly when MABP was reduced below 50 mmHg. However, during stepwise pressure reduction the vasomotion frequency decreased progressively while its amplitude showed a reversed U-shaped curve with a peak at 60-80 mmHg. During hypercapnia, the rhythmical oscillations showed a decrease in both frequency and amplitude, whereas during hypocapnia their frequency did not change but their amplitude increased. These results support the hypothesis that the vasomotion frequency might be dependent of the wall tension and cellular pH while its amplitude could be related to decreased tissue oxygenation.
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PMID:Vasomotion in the rat cerebral microcirculation recorded by laser-Doppler flowmetry. 149 61

We have evaluated the technique of right bronchial intubation for selective right pulmonary ventilation using one lumen tracheal tubes as an alternative to double lumen tubes. We studied 20 patients ASA II-III with a relatively preserved pulmonary function who were programmed for left thoracotomy. We used Shiley nr. 9 or Mallinckrodt nr. 11 tubes. After endotracheal intubation the tube was blindly advanced to the main right bronchus. The position of the tube was assessed by auscultation and it was verified and modified, if necessary, by fibroscopic visualization. The tube was advanced in such a way that Murphy's hole of the endotracheal tube remained in front of the exit of the right superior lobar bronchus. In three patients (15%) blinded placement of the tube was appropriate and in 4 patients (20%) fibroscopic replacement of the tube was required. In the remaining 13 patients (65%) placement of the tracheal tube was considered incorrect: tube rotation in 7 cases, upper placement of the Murphy's hole with respect to the origin of the superior lobar bronchus in 4 cases, and excessive distal placement of Murphy's hole with respect to the superior lobar bronchus in 2 patients. Complications related with the incorrect position of the tube were: leaking of gas into the left bronchium in 5 patients (25%), displacement of the tracheal tube into the main left bronchus requiring withdrawal of the tube to the trachea in one case (5%), hypoxemia (saturation of O2 lower than 90%) in spite of ventilation with FiO2 = 1 in two patients, moderate hypercapnia in three cases, and atelectasis of the right superior lobe during the postoperative phase in three patients (15%).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Selective right bronchial intubation using tracheal tubes under fibroscopic guidance]. 159 78

Literature and our own data on structural and functional state of neocortex and hippocampus during both entrance in hibernation of ground squirrel (Spermophilus undulates) and Wistar rats in hypothermia were generalized. During hibernation when body temperature is about 2-4 degrees C the suppression of both bioelectrical and protein-synthesizing activity, the decrease of neuronal cell bodies and the branching of dendrites, retraction of dendritic spines, and a decrease of postsynaptic active zones of synapses were observed. Similar changes in those parameters were triggered for rats during hypoxia-hypercapnia at body temperature 17-19 degrees C. Hypoxia-hypercapnia facilitates the entrance in torpid state for hole animals. Nonhibernating animals during cooling and hypoxia-hypercapnia trigger functioning some mechanisms similar hibernators during entrance in hibernation. Similar morphological and functional changes for both hibernators and nonhibernators at low temperature state show similarity of mechanisms which induce a low level of brain activity of different animals.
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PMID:[The functional brain state of hibernators and nonhibernators at different animals temperatures]. 2256 29

The effects of potassium comenate on functional state of CNS in mice and rats were studied in the open-field and hole-board tests under control conditions and after acute exposure to hypoxia-hypercapnia. The effects of potassium comenate on CNS were also studied in rodents subjected to propofol-induced sleep. Preliminary administration of 4 mg/kg potassium comenate for 3 days attenuated the posthypoxic changes in behavioral reactions (emotional anxiety/reactivity). The pronounced stress-protective effect of potassium comenate was observed both on days 1 and 14 after exposure to hypoxia-hypercapnia. Under normal conditions, potassium comenate moderated behavioral reactions and augmented somniferous effect of propofol. We hypothesized that the antihypoxic effect of potassium comenate is determined by its stress-protective and sedative potencies.
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PMID:Effect of Potassium Comenate on CNS Functional Status in Rodents Exposed to Combined Hypoxia and Hypercapnia in Comparison with Normally Ventilated Animals. 2770 53