Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 48 patients anaesthetized with nitrous oxide-oxygen and hexobarbitone the neuromuscular (n-m) block (greater than or equal to 95% depression) produced by roughly equipotent doses of d-tubocurarine (dTC), gallamine (GALL), pancuronium (PANC) or alcuronium (ALC), respectively, was antagonized by 10 mg of pyridostigmine (P) applied intravenously 35-460 min after the relaxant at variable levels of spontaneous recovery from n-m block. Muscular reactions to tetanic stimulation (30 to 400 Hz, 4-5 s each) of the ulnar nerve transmitted by a force-displacement system served as a measure for calculating the relative amount of n-m receptors liberated from relaxant molecules. Within 3-10 min after its injection P increased the number of relaxant-free n-m receptors by 16 +/- 6% (M +/- SD). Thereafter recovery progressed at similar speed as before. Reinjections of 5-10 mg P were comparably as effective as the first injection. No correlations were to be found between the effectiveness of P and the dose of relaxant applied (r = 0,12 to 0,27), the level of recovery reached before P (r = 0,32), or the time at which P was injected after the relaxant (r = -0,39), respectively. However, the amount of receptors liberated by P decreased with increasing recovery from n-m block and with increasing time interval between the relaxant and the antidote injection. P was significantly more effective (P less than 0,01), when applied within 150 min after the relaxant than at applications after that time. The relative number of receptors liberated by this drug was insignificantly larger in the PANC-and GALL-block than in the ALC-and dTC-block.
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PMID:[Tetanus-Myomechanographic measurement of receptor liberation by pyridostigmine in neuromuscular block produced by d-tubocurarine, gallamine, pancuronium or alcuronium (author's transl)]. 49 25

Kittens at 10, 20, and 40 days of age were made intermittently hypoxic in 10 or 7% oxygen chambers for either 3 or 8 days. Respiration, EKG, EEG, and neck and eye movements were recorded during hypoxia. Compared to 21% oxygen controls, hypoxic kittens had fewer and shorter epochs of active sleep, and longer epochs of quiet sleep. Some hypoxic kittens exhibited slow and labored respiration during quiet sleep and transitional epochs, which reversed during active sleep. Kittens that showed most pronounced respiratory changes or died had less active sleep than kittens that compensated adequately and survived. These results suggest that active sleep may be important for stimulation of respiration during infancy. Suppression of active sleep, augmentation of quiet sleep, or other disturbances to normal sleep-waking patterns during hypoxia, may increase the risk for hypoxic respiratory depression and death.
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PMID:Sleep-waking patterns in hypoxic kittens. 51 Jul 97

We measured ventilatory responses to CO2 (delta VI/delta PCO2) and transient hypoxia (delta VI/delta SaO2) during reductions of brain blood flow (BBF) to 70% and 50% of control in unanesthetized goats. Increase in inspiratory volume per change in CO2 tension (delta VI/delta PCO2) was measured during rebreathing with sampling of both arterial and cerebral venous blood; increase in inspiratory volume per fall in arterial oxygen saturation (delta VI/delta SaO2) was assessed by the transient N2 inhalation method. Delta VI/delta SaO2 did not significantly change at 70% BBF, but was depressed at 50% BBF. Delta VI/delta PCO2 increased (0.94 +/- 0.18 to 1.29 +/- 0.24 l . min-1 . Torr-1) at 70% BBF if arterial CO2 tension were used to represent the CO2 stimulus but was unchanged if venous CO2 tension were used. At 50% BBF, delta VI/delta PCO2 was depressed (0.38 +/- 0.13 l . min-1 . Torr-1) for both representations of the CO2 stimulus. Brain ischemia increased blood pressure and heart rate but blunted the increase in BBF caused by hypercapnia. We conclude that 1) moderate brain ischemia (70% BBF) does not affect chemosensitivity to hypoxia and CO2, 2) delta VI/delta PCO2 may not be accurately determined from PaCO2 during brain ischemia because cerebrovascular reactivity to CO2 is depressed, and 3) severe brain ischemia (50% BBF) blunts delta VI/delta SaO2 and delta VI/delta PCO2, probably as a consequence of hypoxic depression of the respiratory neurons.
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PMID:Effects of graded reduction of brain blood flow on chemical control of breathing. 53

Total I.V. anesthesia was given to 20 patients using an Etomidate continuous infusion to maintain sleep, combined to Fentanyl analgesia, Droperidol, Pancuronium for muscular relaxation and artificial ventilation with an oxygen-air mixture. All these patients were carefully observed during and for several hours after the anesthesia and the results noted. With the Fentanyl dosages used in this technique, peroperative analgesia was frequently insufficient. More Fentanyl would probably be needed with the inherent dangers of prolonged postoperative depression.
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PMID:Total I.V. anesthesia using a continuous etomidate infusion. 54 55

1. Measurements of milk secretion, mammary oxygen consumption and blood flow, cardiac output and blood pressure have been made in lactating goats exposed to a thermoneutral environment and to two levels of cold stress which were sufficient to raise total body oxygen consumption by an average of 18 and 46% above that in a thermoneutral environment. 2. Mammary blood flow and oxygen consumption were not appreciably affected by the milder cold stress but fell to 63 and 70%, respectively, of their thermoneutral value in the moderately cold environment. Resistance to blood flow through the udder was increased by this level of cold stress and the gland took a smaller fraction of an increased cardiac output. 3. Both levels of cold exposure caused a reduction in milk secretion, to 80 and 40% of its thermoneutral value in the mild and moderate cold respectively. The amount of milk secreted per unit volume of blood flowing through the gland decreased as the severity of the cold stress increased. 4. Voluntary food intake was not affected by the change in environmental temperature but the intake of water was reduced to 55% of the thermoneutral value during mild cold exposure and to 40% of the thermoneutral value during the moderate cold stress. 5. It is concluded that a reduction in blood flow to the mammary gland could be one of several possible mechanisms underlying the depression of milk secretion during cold exposure.
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PMID:Effect of cold exposure on mammary circulation oxygen consumption and milk secretion in the goat. 56 44

The cardiovascular effects of three doses of intravenous fentanyl (50, 100, and 200 microgram) were determined in 42 adult patients undergoing intraabdominal surgical procedures with enflurane (2--3%) and nitrous oxide (50%) in oxygen. Fentanyl was administered a minimum of 40 minutes after induction of anesthesia and 30 minutes after initiation of the surgical procedure. Stroke volume, heart rate, cardiac output, mean arterial and central venous blood pressures, and peripheral arterial resistance were determined by computer analysis of the central aortic pulse-pressure curve according to the method of Warner. Measurements were made before and 2, 4, 6, 8, and 10 minutes after fentanyl. Fentanyl (50 microgram) produced increases in stroke volume and cardiac output as well as a decrease in peripheral arterial resistance but did not alter heart rate or mean arterial blood pressure. Fentanyl (100 microgram) did not significantly change any variable at any time. Fentanyl (1l (200 microgram) produced sustained decreases in stroke volume, cardiac output and mean arterial blood pressure and increased central venous pressure but did not alter heart rate or peripheral arterial resistance. The data indicate that fentanyl (50--100 microgram) stimulates or has no effect on cardiovascular dynamics during enflurane-nitrous oxide anesthesia but fentanyl (200 microgram) produces significant cardiovascular depression. Our findings suggest that small doses of intravenous fentanyl may be of benefit during enflurane-nitrous oxide but larger doses should probably be avoided.
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PMID:Cardiovascular effects of fentanyl during enflurane anesthesia in man. 57 55

In anaesthetized rabbits the influence of vagal cold-block on the ventilatory response to lowered arterial oxygen pressure was investigated. With intact carotid chemoreflexes, lowered PaO2 caused hyperventilation, which was progressively intensified with the degree of hypoxia, regardless of whether the alveolar PCO2 was uncontrolled or kept constant at the hyperoxic control. The V-PaO2 response was to a greater extent due to an increase of respiratory rate than to one of tidal volume. During hyperoxia, vagal cold-block caused a distinct increase in ventilation provided the alveolar PCO2 was not allowed to decrease. During moderate hypoxia, vagal block caused only a slight increase in ventilation, when PACO2 was not controlled, but a distinct decrease in ventilation, when PACO2 was maintained at the hyperoxic level. Without carotid chemoreflexes, lowered PaO2 did not change ventilation at any level, provided the vagus nerves were left intact. This was due to a substantial increase in respiratory rate counteracting a corresponding decrease in tidal volume. Then vagal block led to a ventilatory depression depending on the degree of hypoxia, which was due to a simultaneous decline in respiratory rate and tidal volume. It is concluded that during hypocapnic hypoxia the vagal stretch reflex primarily inhibits the carotid chemoreflex drive of ventilation. During normocapnic hypoxia, however, the mode of interaction between the peripheral and the central chemical drive has to be considered, which without vagal feed-back is occlusive. This occlusion appears to be counteracted by a vagal mechanism sensitive to CO2 in the airways--and possibly also to a lack of O2--, mainly shortening respiratory cycle duration.
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PMID:The role of the vagus nerves in the ventilatory response to lowered PaO2 with intact and eliminated carotid chemoreflexes. 57 48

Anesthestized chinchilla with round window electrodes were placed in a Plexiglas chamber. When they inhaled 100% oxygen at 1 atm, two types of neural effects were observed: 1. fast and reversible AP depression in response to brief exposure to 100% O2; and 2. a slowly developed chronic depression of AP and latency shift due to multiple hyperoxic exposures. The severity of the latter is a function of the dosage of the O2 inhaled, i.e., the concentration of oxygen and the length of time of exposure. For the type-1 effect, carbon dioxide deprivation is felt to be the immediate cause while the type-2 effect is mainly due to O2 toxicity developed at the intracellular level by high O2 concentration. The possible role of superoxide in the auditory O2 toxicity was discussed.
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PMID:Preliminary report on the effects of hyperoxia on cochlear potential in chinchilla. 58 Jan 81

Caesarean sections were performed on 18 Romney ewes on day 144 of pregnancy. Anaesthesia was induced in 9 ewes with CT 1341 and in 9 ewes with thiopentone and maintained in both groups with halothane administered with oxygen. Surgery was performed with the ewes in lateral recumbency, with respiration unassisted. Blood samples were collected from the intact umbilical artery at the time of delivery and analysed for PO2, PCO2, pH (base deficit was derived). The intervals between ewe induction and lamb delivery (lD), delivery and the onset of breathing (TSR), and delivery and the lamb standing were recorded. Lambs in the CT 1341 group both breathed and stood sooner than lambs in the thiopentone group. Significant linear relationships were only found in the CT 1341 group between TSR interval and PCO2 and pH. No significant correlations were found between the lD interval and any of the biochemical characteristics. The results of this study suggest that lateral recumbency does not interfere with uteroplacental circulation, that CT 1341 (2.2 mg/kg) is associated with less neonatal depression than thiopentone (10 mg/kg) and that severe neonatal hypercarbia may delay the onset of respiration in lambs with minimal drug depression.
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PMID:The effects of CT1341, thiopentone and induction- delivery time on the blood gas and acid-base status of lambs delivered by casesarean operation and on the onset of respiration. 58 79

An investigation of the factors that influence the production of dense aerosols of Micropolyspora faeni and Thermoactinomyces vulgaris from hay cultures revealed that the density, freshness, and moisture content of the hay were important influences. Dry aerosols were produced under optimum conditions from hay cultures of either actinomycete and from sterile hay for inhalation challenges to unimmunized rabbits. Depressions in arterial oxygen tensions and hemolytic complement were monitored after such challenge. This investigation showed that hay cultures are capable of inciting a hypersensitivity-like reaction in the lungs, even in the absence of immunization to the organisms contained within the hay, but the entire hypersensitivity reaction cannot be attributed to M. faeni and T. vulgaris alone. Hay itself or other microbial or chemical components appear to have some heat-stable component that possibly contributes to the pathogenesis of the disease.
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PMID:Production of thermophilic actinomycete-hay aerosols for use in experimental hypersensitivity pneumonitis. 59 73


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