Biomedical subjects
Publications and source records attributed to M S Sherman.
Diffuse idiopathic skeletal hyperostosis previously has been reported to cause a number of extraspinal manifestations including dysphagia, respiratory distress, dysphonia and cervical myelopathy. We report a case of cervical DISH so extensive as to interfere with the swallowing mechanism and lead to aspiration. Patients with DISH who have mechanical compression of the posterior pharynx may be at high risk for aspiration.
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A digital computing technique was used to extract continuous calculations of average alveolar pressure and airway resistance from body plethysmographic measurements during forced inspiratory and expiratory vital capacity maneuvers and tidal breathing in human subjects. Derived alveolar pressures were similar to those obtained using an interrupter technique (linear regression slope, 0.99 +/- 0.02; r = 0.98) and by comparison with esophageal pressure measurements. Studies in normal subjects revealed a characteristic pattern of increasing airway resistance throughout the expiratory phases of maximal and submaximal respiratory maneuvers, with maximal resistance of 33 to 110 cm H2O/L/s at low lung volumes during forced vital capacities. In contrast, inspiratory resistance remained low and constant throughout maximal and submaximal inspiratory maneuvers. Patients with COPD showed substantially higher inspiratory and expiratory resistances. In three patients with flow-volume loops suggestive of variable extrathoracic upper airway obstruction, measurements of alveolar pressure and airway resistance made it clear that two of the patients had upper airway obstruction, whereas the other was exerting an inadequate effort. We conclude that this noninvasive technique provides valid estimates of alveolar pressure and airway resistance continuously throughout both phases of the respiratory cycle over a wide range of volumes and flow rates. It may prove to be useful in the assessment of effort and airway obstruction in patients with a variety of pulmonary conditions.
We evaluated the effect of glucagon on eight patients with asthma. After withholding bronchodilators for 12 hours, patients received either 2 units of intravenous glucagon or 2 ml of saline after a double-blind crossover protocol. Glucagon significantly improved the FEV1 (17.5% +/- 5.5 SEM) and the peak expiratory flow rate (14.2% +/- 4.9), compared to placebo (-2.4% +/- 2.9, p less than 0.02; 4.5% +/- 4.1, p less than 0.25, respectively). Seven patients had an excellent response to glucagon (40% to 105% of the response to inhaled isoproterenol), but four patients had no significant response. We conclude that glucagon, through its pharmacologic actions, can have a bronchodilator effect in selected patients with asthma.
Digoxin could improve diaphragm contractility and fatigability if inhibition of sodium-potassium adenosine triphosphatase enhances calcium influx from extracellular sources, or it could impair contractility and worsen fatigue if it impairs maintenance of the membrane potential. We studied the effects of digoxin on isometric force production, fatigue, and recovery in isolated, directly stimulated, guinea pig and rat diaphragms. Digoxin had no effect on maximal twitch or tetanic tensions compared with control diaphragms in either rat (2 ng/ml to 20 micrograms/ml) or guinea pig (2 ng/ml to 2 micrograms/ml) hemidiaphragms. Digoxin worsened high frequency fatigue and impaired recovery from fatigue in guinea pigs (200 ng/ml to 2 micrograms/ml) but not in rat (2 micrograms/ml) hemidiaphragms. We conclude that digoxin has no effect on diaphragm contractility. Hypopolarization of the membrane potential is the likely cause for the increased fatigability. The difference in responsiveness between species is likely due to insensitivity of rat sodium-potassium adenosine triphosphatase to digoxin.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Determination of alpha-fetoprotein (AFP) in the 1- to 500-mug/litre range has been shown to be of diagnostic value in a variety of clinical settings, in particular, in prenatal diagnosis and the monitoring of pregnancies. A modified paper disc sandwich radioimmunoassay (sandwich RIA) is described which meets the essential criteria for large-scale assaying for AFP. The sandwich RIA is based upon anti-AFP antiserum, which is available commercially, and thus purified AFP is not essential. The sandwich RIA (1) is simple to run and gives results within 24 h; (2) has a comparatively broad range of sensitivity; (3) requires no apparatus other than a gamma-scintillation counter, and (4) has an acceptable level of accuracy. We have used the described sandwich RIA for AFP in routine obstetrical practice for over 2 years. Our experience, encompassing more than 15,000 samples, has been most satisfactory.