Respiration physiology最新文献_第10页

Stretch induces a growth factor in alveolar cells via protein kinase 拉伸通过蛋白激酶诱导肺泡细胞的生长因子

Respiration physiology Pub Date : 2001-09-01 DOI: 10.1016/S0034-5687(01)00244-4

Hiroyuki Yamamoto, Hidemi Teramoto, Kohsaku Uetani, Katsutoshi Igawa, Eiji Shimizu

引用次数: 47

High strength stimulation of the vagus nerve in awake humans: a lack of cardiorespiratory effects 对清醒的人的迷走神经的高强度刺激:缺乏心肺作用

Respiration physiology Pub Date : 2001-09-01 DOI: 10.1016/S0034-5687(01)00252-3

A.P Binks , D Paydarfar , S.C Schachter , A Guz , R.B Banzett

{"title":"High strength stimulation of the vagus nerve in awake humans: a lack of cardiorespiratory effects","authors":"A.P Binks , D Paydarfar , S.C Schachter , A Guz , R.B Banzett","doi":"10.1016/S0034-5687(01)00252-3","DOIUrl":"10.1016/S0034-5687(01)00252-3","url":null,"abstract":"<div>Vagus nerve stimulation is used to reduce the frequency and intensity of seizures in patients with epilepsy. In the present study four such patients were studied while awake. We analyzed the physiological responses to vagus nerve stimulation over a broad range of tolerable stimulus parameters to identify vagal A-fiber threshold and to induce respiratory responses typical of C-fiber activation. A-fiber threshold was determined by increasing stimulation current until laryngeal motor A-fibers were excited (frequency=30 Hz). With A-fiber threshold established, C-fiber excitation was attempted with physiologically appropriate stimulus parameters (low frequency and high amplitude). Results: A-fiber thresholds were established in all patients, threshold currents ranged between 0.5 and 1.5 mA. Stimulation at lower frequency (2–10 Hz) and higher amplitudes (2.75–3.75 mA) did not produce cardiorespiratory effects consistent with C-fiber activation. It is possible that such effects were not observed because vagal C-fibers were not excited, because C-fiber effects were masked by the ‘wakeful drive’ to breathe, or because epilepsy or the associated therapy had altered central processing of the vagal afferent inputs.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00252-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89505755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 58

The morphology of periodic breathing in infants and adults 婴儿和成人周期性呼吸的形态学

Respiration physiology Pub Date : 2001-09-01 DOI: 10.1016/S0034-5687(01)00249-3

Zalman Weintraub , Don Cates , Kim Kwiatkowski , Khalid Al-Hathlol , Aamir Hussain , Henrique Rigatto

{"title":"The morphology of periodic breathing in infants and adults","authors":"Zalman Weintraub , Don Cates , Kim Kwiatkowski , Khalid Al-Hathlol , Aamir Hussain , Henrique Rigatto","doi":"10.1016/S0034-5687(01)00249-3","DOIUrl":"10.1016/S0034-5687(01)00249-3","url":null,"abstract":"<div>To test the hypothesis that the crescendo–decrescendo type of pattern of periodic breathing is more common in infants than in adulthood, we examined the morphologies of periodic breathing in four groups of subjects: group 1 (n=10, gestational age 30±1 week), group 2 (n=10, GA 31±1 week), group 3 (n=10, GA 38±1 week), and group 4 (n=10, age 50±4 years). Respiratory pattern and ventilation were measured using a flow-through system. The breathing morphologies were defined according to the respiratory flow. We found (1) a predominant crescendo–decrescendo pattern in preterm infants (groups 1 and 2, >50%) and this changed to a predominant decrescendo breathing in adults (group 4, 50%); (2) total breathing cycle and its phases did not change significantly among the neonatal groups, but they almost doubled in adult subjects; however, the number of breaths per breathing interval remained the same (crescendo–decrescendo) or less (flat and decrescendo) in adults as compared to preterm infants; (3) the duty cycle (breathing interval/cycle duration) remained consistent with age; and (4) at the beginning of each breathing interval, alveolar Pco2 was highest and alveolar Po2 and O2 saturation lowest. The findings suggest a change in the strategy of the respiratory control system during periodic breathing between the infant and the adult, perhaps dictated by mechanical and chemoreceptor limitations early in age, with a switch from a crescendo–decrescendo to a predominantly decrescendo pattern.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00249-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79560383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 23

High Altitude Medicine and Physiology, Edited by M. P. Ward, J. S. Milledge and J. B. West, 3rd Edition, Arnold, London, 2000

Respiration physiology Pub Date : 2001-08-01 DOI: 10.1016/S0034-5687(01)00235-3

Henry Gautier

引用次数: 1

Prenatal exposure to nicotine impairs protective responses of rat pups to hypoxia in an age-dependent manner 产前暴露于尼古丁损害了大鼠幼崽以年龄依赖的方式对缺氧的保护反应

Respiration physiology Pub Date : 2001-08-01 DOI: 10.1016/S0034-5687(01)00232-8

James E Fewell, Francine G Smith, Vienna K.Y Ng

{"title":"Prenatal exposure to nicotine impairs protective responses of rat pups to hypoxia in an age-dependent manner","authors":"James E Fewell, Francine G Smith, Vienna K.Y Ng","doi":"10.1016/S0034-5687(01)00232-8","DOIUrl":"10.1016/S0034-5687(01)00232-8","url":null,"abstract":"<div>Experiments were carried out on rat pups to investigate the interaction between prenatal exposure to nicotine and postnatal age on protective responses that promote survival during exposure to hypoxia. From days 6 or 7 of gestation, pregnant rats received either nicotine (∼6 mg of nicotine tartrate/kg of body weight per day) or vehicle continuously via a 28-day osmotic minipump. On postnatal days 1–2, 5–6 and 10–11, the pups were exposed either to a single period of hypoxia produced by breathing an anoxic gas mixture (97% N2 and 3% CO2) and their time to last gasp determined, or they were exposed repeatedly to hypoxia and their ability to autoresuscitate from primary apnea determined. Prenatal exposure to nicotine decreased the time to last gasp, but only in the 1–2-day-old animals. The total number of gasps was, however, increased in this age group due to the effect of nicotine on the gasping pattern. Furthermore, prenatal exposure to nicotine decreased the number of successful autoresuscitations and influenced the cardiorespiratory events preceding death in the 1–2- and 5–6-day-old pups but not in the 10–11-day-old pups. Thus, our experiments show that prenatal exposure to nicotine impairs protective responses of rat pups that may sustain life during exposure to hypoxia in an age-dependent manner.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00232-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86556056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 85

Airway ammonia negates the normal ventilatory response to airway CO2 in garter snakes 在吊带蛇气道氨否定正常通气反应气道二氧化碳

Respiration physiology Pub Date : 2001-08-01 DOI: 10.1016/S0034-5687(01)00216-X

Marcos Vivoni, Maria I Castro , Liliana Lojo, Robert A Furilla

{"title":"Airway ammonia negates the normal ventilatory response to airway CO2 in garter snakes","authors":"Marcos Vivoni, Maria I Castro , Liliana Lojo, Robert A Furilla","doi":"10.1016/S0034-5687(01)00216-X","DOIUrl":"10.1016/S0034-5687(01)00216-X","url":null,"abstract":"<div>Earlier studies from this lab showed that unidirectionally ventilated snakes, maintained on high airway [CO2], breathe slowly with a large tidal volume. If airway [CO2] is abruptly reduced during inspiration, inspiratory duration (ti) and tidal volume increase. On the other hand, in an animal normally receiving fresh air (no CO2 in the inspired air) on each inspiration, if fresh air is withheld for one breath, ti and tidal volume decrease. To test the effect of producing an alkaline environment in the presence of CO2 during these two maneuvers, six unidirectionally ventilated snakes weighing 32±16 g were maintained on 4% CO2 in air flowing at 300 ml/min even during inspiration. NH3 (4%) was introduced into the lung during one inspiration. During that breath, ti increased significantly, as if CO2 had been removed from the lung. In another study, six different snakes weighing 21±6 g received fresh air at each inspiration. At the end of inspiration [CO2] was again raised to 4%. However, for one breath, [CO2] was maintained high during inspiration and airway NH3 (3–4%) was simultaneously introduced into the airstream. During this breath, ti was expected to decrease, owing to the elevated [CO2]; however, there was no significant difference in the ti of the test breath compared with the previous breath, indicating that ammonia interfered with the expected CO2 response. This study suggests that pH (probably intracellular) rather than PCO2 produces this ventilatory reflex.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00216-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88562873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Effect of series of resistance levels on flow limitation in mechanically ventilated COPD patients 一系列阻力水平对机械通气COPD患者血流限制的影响

Respiration physiology Pub Date : 2001-08-01 DOI: 10.1016/S0034-5687(01)00236-5

Marlies S Lourens, Bart van den Berg, Anton F.M Verbraak, Henk C Hoogsteden, Jan M Bogaard

{"title":"Effect of series of resistance levels on flow limitation in mechanically ventilated COPD patients","authors":"Marlies S Lourens, Bart van den Berg, Anton F.M Verbraak, Henk C Hoogsteden, Jan M Bogaard","doi":"10.1016/S0034-5687(01)00236-5","DOIUrl":"10.1016/S0034-5687(01)00236-5","url":null,"abstract":"<div>In severe chronic obstructive pulmonary disease (COPD) lung emptying is disturbed by airways compression and expiratory flow limitation. Application of an external resistance has been suggested to counteract airways compression and improve lung emptying. We studied the effect of various resistance levels on lung emptying in mechanically ventilated COPD patients. In 18 patients an adjustable resistor was applied. The effect on airways compression was assessed by iso-volume pressure–flow curves (IVPF) and by interrupter measurements. Respiratory mechanics during unimpeded expirations were correlated to the results obtained with the resistances. The resistances caused an increase in iso-volume flow at the IVPF-curves in six patients, indicating that airways compression was counteracted. Interrupter measurements showed that overshoots in flow (as measure of flow limitation) were significantly reduced by the resistor. These effects could be predicted on basis of respiratory mechanics during unimpeded expiration. In conclusion, mechanically ventilated COPD patients can be identified in whom application of external resistances counteracts airways compression and reduces flow limitation.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00236-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77634741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

Simulation of acute spinal cord injury: effects on respiration 急性脊髓损伤模拟:对呼吸的影响

Respiration physiology Pub Date : 2001-08-01 DOI: 10.1016/S0034-5687(01)00237-7

N.M Skjodt, R.P Farran, H.G Hawes, J.B Kortbeek, P.A Easton

{"title":"Simulation of acute spinal cord injury: effects on respiration","authors":"N.M Skjodt, R.P Farran, H.G Hawes, J.B Kortbeek, P.A Easton","doi":"10.1016/S0034-5687(01)00237-7","DOIUrl":"10.1016/S0034-5687(01)00237-7","url":null,"abstract":"<div>The respiratory effects of acute spinal injury and paralysis are difficult to study. Urgent medical needs of human spinal cord injury victims usually preclude study, while induction of spinal cord lesions in awake animals is not feasible ethically. We utilized controlled, segmental infusion of epidural anesthetic in awake, highly trained, implanted canines to reversibly simulate the effects of thoracic and cervical (paraplegic and quadriplegic) spinal cord injury. We studied six animals, an average of 29 days after implantation with electromyogram and sonomicrometry transducers in transversus abdominis, external intercostal, parasternal intercostal and costal diaphragm muscles. Anesthetic was infused through an epidural catheter inserted percutaneously, under fluoroscopic guidance. Asymmetrical motor blockade was prevented using repositioning during epidural infusions. By sequential infusion we were able to induce three distinct, functional levels of spinal paralysis showing cumulative paralysis of abdominal, external intercostal, and parasternal intercostal muscles. Paralysis of the abdomen and chest wall, sparing only the diaphragm, showed unexpected bradypnea and failure to maintain minute ventilation.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00237-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83367537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Genioglossal inspiratory activation: central respiratory vs mechanoreceptive influences 颏舌吸气激活:中枢呼吸与机械感受的影响

Respiration physiology Pub Date : 2001-08-01 DOI: 10.1016/S0034-5687(01)00230-4

Giora Pillar, Robert B Fogel, Atul Malhotra, Josée Beauregard, Jill K Edwards, Steven A Shea, David P White

{"title":"Genioglossal inspiratory activation: central respiratory vs mechanoreceptive influences","authors":"Giora Pillar, Robert B Fogel, Atul Malhotra, Josée Beauregard, Jill K Edwards, Steven A Shea, David P White","doi":"10.1016/S0034-5687(01)00230-4","DOIUrl":"10.1016/S0034-5687(01)00230-4","url":null,"abstract":"<div>Upper airway dilator muscles are phasically activated during respiration. We assessed the interaction between central respiratory drive and local (mechanoreceptive) influences upon genioglossal (GG) activity throughout inspiration. GGEMG and airway mechanics were measured in 16 awake subjects during baseline spontaneous breathing, increased central respiratory drive (inspiratory resistive loading; IRL), and decreased respiratory drive (hypocapnic negative pressure ventilation), both prior to and following dense upper airway topical anesthesia. Negative epiglottic pressure (Pepi) was significantly correlated with GGEMG across inspiration (i.e. within breaths). Both passive ventilation and IRL led to significant decreases in the sensitivity of the relationship between GGEMG and Pepi (slope GGEMG vs Pepi), but yielded no change in the relationship (correlation) between GGEMG and Pepi. During negative pressure ventilation, pharyngeal resistance increased modestly, but significantly. Anesthesia in all conditions led to decrements in phasic GGEMG, increases in pharyngeal resistance, and decrease in the relationship between Pepi and GGEMG. We conclude that both central output to the GG and local reflex mediated activation are important in maintaining upper airway patency.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00230-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73057685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 59

In memoriam Stephen Marsh Tenney (1922–2000) 史蒂芬·马什·坦尼(1922-2000)

Respiration physiology Pub Date : 2001-08-01 DOI: 10.1016/S0034-5687(01)00194-3

Donald Bartlett Jr., Pierre Dejours

引用次数: 0