A novel determination method for a new inhalation anaesthetic, sevoflurane, in a closed circuit in the presence of carbon dioxide absorbents is investigated using gas chromatography/selected ion monitoring with xenon as an internal standard. The decrease rate of sevoflurane with soda lime was 0.22% +/- 0.158/h (mean +/- SD), while that with baralyme was 0.57% +/- 0.115/h (mean +/- SD).

Anesthesia, Inhalation↗

PubMedDate not supplied

The quantitative analysis of inhalational anaesthetics in forensic samples by gas chromatography/mass spectrometry/selected ion monitoring.

The quantitative analysis of volatile anaesthetics for biomedical applications by means of gas chromatograph/mass spectrometry/selected ion monitoring (GC/MS/SIM) was studied. Xenon gas was selected as an internal standard for the assay by adding to a closed system, because of its stability and inactivity. In the assay of inhalational anaesthetics, isoflurane and nitrous oxide (laughing gas), in forensic samples (serum and cerebrospinal fluid), the calibration of the anaesthetic was linear from 0.12 to 12 nmol/mL in isoflurane and from 30 to 300 nmol/mL in nitrous oxide. Our results suggest that this new method is suitable for the quantitative analysis of inhalational anaesthetics in the biomedical field.

Anesthetics, Inhalation↗

PubMedDate not supplied

Dynamic MRI of transcorneal dispersion of oxygen into the anterior chamber of human eye.

To measure the transcorneal dispersion of oxygen into the anterior chamber, dynamic T1-weighted fast-spin-echo MRI (TR=2 seconds, TE=15 msec, 5-mm slice) of the human eye was performed both before and during oxygen supply to a full goggle placed on the face. During the course of the imaging, a significant increase in the signals in the anterior chamber occurred. This indicated that transcorneal dispersion of oxygen into the anterior chamber can be evaluated by this procedure, suggesting that this method may be useful for diagnosing dysfunction of the cornea or aqueous flow.

Analysis of Variance↗

PubMedDate not supplied

Protective effect of histidine on iron (II)-induced hydroxyl radical generation in rat hearts.

We investigated the efficacy of histidine on iron (II)-induced hydroxyl radical (.OH) generation in extracellular fluid of the rat myocardium using a flexibly mounted microdialysis technique (O system). Rats were anesthetized and a microdialysis probe was implanted in the left ventricular, followed by infusion of sodium salicylate in Ringer's solution (0.5 nmol/microL/min) to detect the generation .OH as reflected by the non-enzymatic formation of 2,3-dihydroxybenzoic acid (DHBA). Iron (II) clearly produced a concentration-dependent increase in .OH formation. A positive linear correlation between iron (II) and the formation of 2,3-DHBA (R2 = 0.987) was observed. However, histidine (25 mM) was infused through a microdialysis probe; iron (II) failed to increase the 2,3-DHBA formation obtained. To examine the effect of histidine on ischemia-reperfusion of the myocardium, the heart was subjected to myocardial ischemia for 15 min by occlusion of the left anterior descending coronary artery (LAD). When the heart was reperfused, a marked elevation of the levels of 2,3-DHBA was observed in the heart dialysate. When corresponding experiments were performed with histidine (25 mM)-pretreated animals, histidine prevented the ischemia-reperfusion induced .OH generation trapped as 2,3-DHBA. These results indicate that histidine protects the myocardium against ischemia-reperfusion damage by .OH generation.

Animals↗

PubMedDate not supplied

Continuous isoproterenol inhalation therapy in children with severe asthmatic attack.

We studied the 1-type isoproterenol inhalation therapy for patients with severe asthmatic attacks who were admitted at the Department of Allergy of National Children's Hospital from 1981 to 1991. One hour after l-type isoproterenol inhalation therapy, statistically significant effects were noted with regard to the asthmatic status. Moreover, no side effect was found amoung the subjects. From these data, 1-type isoproterenol inhalation therapy is thought to be effective for severe asthmatic attacks.

Administration, Inhalation↗

PubMedDate not supplied

Drug effects on exercise-induced late asthmatic responses.

Disodium cromoglycate, prednisolone, beclomethasone and salbutamol were administered prior to the cycle ergometer exercise task separately to different groups of children with exercise-induced dual asthmatic reaction. Pre-treatment with disodium cromoglycate of ten asthmatics totally inhibited the dual reaction. Prednisolone treatment of eleven asthmatics and beclomethasone treatment of five asthmatics did not inhibit the early response but only the late response. Salbutamol treatment of ten asthmatics mainly inhibited the early phase reaction. Changes in neutrophil chemotactic activity correlated with airflow limitation in the disodium cromoglycate and prednisolone study, however, there were some discrepancies between the changes in FEV1 and neutrophil chemotactic activity in the beclomethasone and salbutamol studies. These findings suggest that exercise-induced dual asthmatic reaction are modified by disodium cromoglycate, prednisolone, beclomethasone or salbutamol in a mechanism which may be different in each drug and that there are similarities in the inflammatory responses in antigen- and exercise-induced dual asthmatic responses.

Albuterol↗