ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Maie LEW/f Mai rats were exposed to an atmosphere of 20 per cent N2O, 20 per cent O2, and 60 per cent N2for a maximum of 35 days. Evidence of injury to the seminiferous tubules was found in some animals by the second day By 14 days, such damage was found in all animals, the toxic effect was confined to the spermatogenic cells, with consequent reduction in mature spermatozoa and appearance of multinucleated forms, Other cells within the testes were resistant to damage. Recovery of spermatogenesis occurred apparatus. after return to room air for more than three days, Serum testosterone levels were not significantly affected during the prolonged exposure.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

A nitrogen-dilution technique for measurement of airway closing volumes (CV) and functional residual capacity (FRC) not requiring subject cooperation was tested in five healthy, awake, spontaneously breathing subjects and subsequently used in 20 patients during anesthesia with mechanical ventilation. Incomplete exhalation before inhalation of oxygen did not significantly alter CV. Inspiration of a volume of oxygen equal to 75 per cent of vital capacity (VC) did not affect CV, whereas inspiration to 50 percent VC resulted in a 20 per cent decrease in CV. Expiratory resistance tended to reduce CV. By means of this technique, the validity of which had been thus demonstrated, airway closure could be shown to occur at lung volumes larger than FRC (and thus within a normal tidal volume) in six patients prior to anesthesia, and in a further II (total 17 of 20) during anesthesia with mechanical ventilation. FRC decreased by an average of 0.5 liters during anesthesia with mechanical ventilation and was only 0,2 liters above residual volume. Significant hypoxemia was observed in association with airway closure.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Metabolic, hemodynamic and neuroendocrine responses to the combined use of halothane and succinylcholine (SCh) were measured in five normal swine and five swine susceptible to malignant hyperthermia (MH). Constant-volume ventilation was used, and no therapy was instituted. The overall response in susceptible swine was fulminant, in that it involved the rapid onset of SCh-induced MH combined with the more severe metabolic, endocrine, and cardiovascular effects of halothane-induced MH. Maximal changes in Vo2were equivalent with cither drug or both combined, while changes in lactate, potassium (K+),pH, and catecholamines were perhaps synergistic. Utilizing similar measurements, procaine or procainamide was used in 20 susceptible swine in attempts to prevent MH initiated by halothane, SCh, or both. Recommended therapeutic doses of either drug did not prevent characteristic MH changes in oxygen consumption, cardiac output, lactate. K+,pH. catecholamines, or temperantre.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Effects of lidocaine on arterial pressure, heart rate and electrocortical activity were studied in nine fetal lambs at 0.77 to 0.92 gestation (116 to 138 days of gestation; term in sheep is 150 days). Lidocaine was administered into a fetal femoral vein either as a continuous infusion or as a bolus injection. Epileptiform activity was observed in all fetuses both after continuous infusion and after bolus injection of lidocaine. Fetal arterial concentrations of lidocaine at the time of the first epileptiform discharge during continuous infusion ranged from G.9 to 40.0 μg/ml, and correlated negatively with gestational age (Y = −1.727 × +242.7; r= −0.94). The increases in fetal mean arterial pressure during epileptiform bursts correlated directly with the gestational age (Y = 1.27 × −150.0; r = 0.91). The convulsive doses of lidocaine injected as a bolus ranged from 8.0 to 34.1 mg/kg, and correlated negatively with gestational age (Y = −0.991 × +144.9; r= −0.88). The increased sensitivity to lidocaine of the fetal central nervous system with advancing gestation probably reflects differences in fetal brain development. The increase in cardiovascular responses to epileptiform activity with advancing gestation could be related to differences cither in the strength of epileptiform discharges or in permeability of the blood–brain barrier to lidocaine, or to immaturity of the autonomie nervous supply to the cardiovascular system in young fetuses.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Rats were given standardized injections of3H-L-proline into the trigeminal ganglion and14C-lidocaine hydrochloride at the infraorbital foramen. The3H-L-proline was always injected 2.5 h before removal of the nerve. Lidocaine, 1,2, and 4 per cent, produced a concentration-related inhibition of entry of3H-labeled rapid axonal transport into the distal portions of the nerve. Addition of epinephrine, 1:200,000, doubled the intensify of the effect. The time delay of recovery was also concentration-related, and with 4 per cent lidocaine recovery' still seemed incomplete after 4.5 h. It is concluded that inhibition of rapid axonal transport is probably a usual byproduct of nerve block with local anesthetics such as lidocaine. The inhibition seems attributable in part to a disturbance of the energy metabolism of the nerve.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Responses to radiant-heat stimulation to the back of the hand were obtained during baseline conditions and during acupuncture sessions. Signal-detection methodology and analysis were used to determine whether acupuncture affects d' (changes physiologic processes) relative to pain report. A binary rather than a rating-scale procedure was used to obtain more accurate measures of sensitivity. Results indicated that acupuncture decreased sensitivity only at intensity levels that were never described as painful.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Both theophylline and halothane inhibited transformation of human lymphocytes by phytohemag-glutinin (PHA). Theophylline did not augment the inhibitory action of halothane and depressed PHA transformation of halolhane-treated cells to the same extent as that of air-treated cells. Halothane- and air-treated lymphocytes, prior to PHA addition, had the same content of cyclic AMP. The addition of PHA to these cultures raised cyclic-AMP concentrations to the same extent in halothane- and air-treated lymphocytes. Halothane action on PHA-stimuluted lymphocytes appears not to involve changes in cyclic nucleotide metabolism.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID