The Use of Phenmetrazine Hydrochloride (Preludin) in the Obese Diabetic     

W. Leith  J. C. Beck 《CMAJ》1958,79(11):897-898

  相似文献   

Bortezomib-resistant nuclear factor-kappaB activity in multiple myeloma cells     

Markovina S  Callander NS  O'Connor SL  Kim J  Werndli JE  Raschko M  Leith CP  Kahl BS  Kim K  Miyamoto S 《Molecular cancer research : MCR》2008,6(8):1356-1364

  相似文献   

    

McCool  F. D.; Tzelepis  G. E.; Leith  D. E.; Hoppin  F. G.  Jr 《Journal of applied physiology》1989,66(5):2045-2055

When a subject breathes against an inspiratory resistance, the inspiratory pressure, the inspiratory flow, and the lung volume at which the breathing task takes place all interact to determine the length of time the task can be sustained (Tlim). We hypothesized that the mechanism actually limiting tasks in which these parameters were varied involved the rate of energy utilization by the inspiratory muscles. To test this hypothesis, we studied four experienced normal subjects during fatiguing breathing tasks performed over a range of pressures and flows and at two different lung volumes. We assessed energy utilization by measuring the increment in the rate of whole body O2 consumption due to the breathing task (VO2 resp). Power and mean esophageal pressure correlated with Tlim but depended also on lung volume and inspiratory flow rate. In contrast, VO2 resp closely correlated with Tlim, and this relationship was not systematically altered by inspiratory flow or lung volume. The shape of the VO2 resp vs. Tlim curve was approximately hyperbolic, with high rates of VO2 resp associated with short endurance times and lower rates of VO2 resp approaching an asymptotic value at high Tlim. These findings are consistent with a mechanism whereby a critical rate of energy utilization determines the endurance of the inspiratory pump, and that rate varies with pressure, flow, and lung volume.  相似文献   

    

A. D. Leith Napier  W. Ramsay Smith 《BMJ (Clinical research ed.)》1900,2(2070):608

  相似文献   

Reconsidering survival     

Mark Leith 《CMAJ》2007,177(9):1148

  相似文献   

    

Potard  U. Silke Birlenbach; Leith  David E.; Fedde  M. Roger 《Journal of applied physiology》1998,84(6):2052-2059

Thoroughbred (TB) and draft horses (DH) havelong been selected for tasks of very different intensities andforce-speed relationships. To study their adaptations, we measuredO₂ consumption and related variables in three TB and four DH during progressive exercise tests ona level treadmill. The horses exerted a draft force of 0, 5, 10, 15, or20% of their body weight at speeds that increased by 2 m/s every 3 minuntil they could not maintain that speed. We found that TB could exertthe same draft forces as DH and, at each force, TB achieved about twicethe speed, twice the external power, and twice theO₂ consumption as DH; thus the twobreeds had the same gross efficiencies. We also found maximalO₂ consumption of TB to be abouttwice that of DH (134 vs. 72 ml · kg¹ · min¹,respectively), suggesting adaptations to high-intensity exercise. Peakefficiency was reached at lower speeds in DH than in TB, suggestingadaptations to high-force, low-speed exercise. These differencesbetween TB and DH in force-speed and aerobic capacities and in speedfor peak efficiency likely reflect different contraction velocities inlocomotor muscles.

  相似文献   

    

Vinegar  A.; Sinnett  E. E.; Leith  D. E. 《Journal of applied physiology》1979,46(5):867-871

  相似文献   

    

F D McCool  M B Hershenson  G E Tzelepis  Y Kikuchi  D E Leith 《Journal of applied physiology》1992,73(1):36-43

The inspiratory muscles can be fatigued by repetitive contractions characterized by high force (inspiratory resistive loads) or high velocities of shortening (hyperpnea). The effects of fatigue induced by inspiratory resistive loaded breathing (pressure tasks) or by eucapnic hyperpnea (flow tasks) on maximal inspiratory pressure-flow capacity and rib cage and diaphragm strength were examined in five healthy adult subjects. Tasks consisted of sustaining an assigned breathing frequency, duty cycle, and either a \"pressure-time product\" of esophageal pressure (for the pressure tasks) or peak inspiratory flow rate (for the flow tasks). Esophageal pressure was measured during maximal inspiratory efforts against a closed glottis (Pesmax), maximal transdiaphragmatic pressure was measured during open-glottis expulsive maneuvers (Pdimax), and maximal inspiratory flow (VImax) was measured during maximal inspiratory efforts with no added external resistance before and after fatiguing pressure and flow tasks. The reduction in Pesmax) with pressure fatigue (-25 +/- 7%) was significantly greater than the change in Pesmax with flow fatigue (-8 +/- 8%, P less than 0.01). In contrast, the reductions in Pdimax (-11 +/- 8%) and VImax (-16 +/- 3%) with flow fatigue were greater than the changes in Pdimax (-0.6 +/- 4%, P less than 0.05) or VImax (-3 +/- 4%, P less than 0.05) with pressure fatigue. We conclude that respiratory muscle performance is dependent not only on the presence of fatigue but whether fatigue was induced by pressure tasks or flow tasks. The specific impairment of Pesmax and not of Pdimax or flow with pressure fatigue may reflect selective fatigue of the rib cage muscles.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

    

R L Pieschl  P W Toll  D E Leith  L J Peterson  M R Fedde 《Journal of applied physiology》1992,73(6):2297-2304

To determine the factors responsible for changes in [H+] during and after sprint exercise in the racing greyhound, Stewart's quantitative acid-base analysis was applied to arterial blood plasma samples taken at rest, at 8-s intervals during exercise, and at various intervals up to 30 min after a 402-m spring (approximately 30 s) on the track. [Na+], [K+], [Cl-], [total Ca], [lactate], [albumin], [Pi], PCO2, and pH were measured, and the [H+] was calculated from Stewart's equations. This short sprint caused all measured variables to change significantly. Maximal changes were strong ion difference decreased from 36.7 meq/l at rest to 16.1 meq/l; [albumin] increased from 3.1 g/dl at rest to 3.7 g/dl; PCO2, after decreasing from 39.6 Torr at rest to 27.9 Torr immediately prerace, increased during exercise to 42.8 Torr and then again decreased to near 20 Torr during most of recovery; and [H+] rose from 36.6 neq/l at rest to a peak of 76.6 neq/l. The [H+] calculated using Stewart's analysis was not significantly different from that directly measured. In addition to the increase in lactate and the change in PCO2, changes in [albumin], [Na+], and [Cl-] also influenced [H+] during and after sprint exercise in the running greyhound.  相似文献   

Puerperal Eclampsia: A Comparison with Venom Poisoning and a Suggestion for Treatment following therefrom     

H. Leith Murray 《BMJ (Clinical research ed.)》1911,1(2613):185-187

  相似文献