Methods to Assess Breathlessness in Healthy Subjects: A Critical Evaluation and Application to Analyse the Acute Effects of Diazepam and Promethazine on Breathlessness Induced by Exercise or by Exposure to Raised Levels of Carbon Dioxide

1981 ◽  
Vol 61 (4) ◽  
pp. 429-439 ◽  
Author(s):  
R. D. Stark ◽  
S. A. Gambles ◽  
J. A. Lewis
Keyword(s):  
Carbon Dioxide ◽  
Healthy Subjects ◽  
Critical Evaluation ◽  
Double Blind Study ◽  
Double Blind ◽  
Cardiorespiratory Function ◽  
Graded Exercise ◽  
High Level ◽  
A Minor ◽  
The Relationship

1. Methods were devised and evaluated for inducing breathlessness by submaximal graded exercise in healthy subjects while objective measurements of cardiorespiratory function were made. Breathlessness was assessed with serial visual analogue scales (VAS), but with various measures to enhance repeatability. 2. A high level of reproducibility was obtained in spite of the subjective nature of the assessment. Individual responses were described by the relationship between breathlessness and ventilation. The sensitivity of the method was demonstrated by the use of inspiratory resistances which disturbed this relationship and caused greater breathlessness for a given level of ventilation. 3. These methods were applied to six healthy subjects to analyse the effects of acute doses of diazepam and promethazine on breathlessness induced by graded exercise or by rebreathing carbon dioxide in a double-blind study. 4. During exercise, diazepam and promethazine did not reduce breathlessness, although there was a minor trend with promethazine. During exposure to elevated levels of carbon dioxide, diazepam and promethazine had no effect on breathlessness. Diazepam and promethazine produced similar levels of sedation, but neither drug had significant effects on the ventilatory response to carbon dioxide. These preliminary findings contrast with those reported for chronic diazepam in ‘pink puffers’. 5. Raised levels of carbon dioxide caused greater breathlessness in relation to ventilation than did exercise.

Evaluation of the Efficacy of ST2 and NT-proBNP in the Diagnosis and Prediction of Short- Term Prognosis in Heart Failure with Reduced Ejection Fraction

2017 ◽  
Vol 9 (04) ◽  
Author(s):  
Shivananda B Nayak ◽  
Dharindra Sawh ◽  
Brandon Scott ◽  
Vestra Sears ◽  
Kareshma Seebalack ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Cardiac Biomarkers ◽  
Double Blind Study ◽  
Short Term ◽  
Double Blind ◽  
Reduced Ejection Fraction ◽  
The Mean ◽  
Design And Methods ◽  
The Relationship

Purpose: i) To determine the relationship between the cardiac biomarkers ST2 and NT-proBNP with ejection fraction (EF) in heart failure (HF) patients. ii) Assess whether a superiority existed between the aforementioned cardiac markers in diagnosing the HF with reduced EF. iii) Determine the efficacy of both biomarkers in predicting a 30-day cardiovascular event and rehospitalization in patients with HF with reduced EF iv) To assess the influence of age, gender, BMI, anaemia and renal failure on the ST2 and NT-proBNP levels. Design and Methods: A prospective double-blind study was conducted to obtain data from a sample of 64 cardiology patients. A blood sample was collected to test for ST2 and NT-proBNP. An echocardiogram (to obtain EF value), electrocardiogram and questionnaire were also obtained. Results: Of the 64 patients enrolled, 59.4% of the population had an EF less than 40%. At the end of the 30- day period, 7 patients were warded, 37 were not warded, one died and 17 were non respondent. Both biomarkers were efficacious at diagnosing HF with a reduced EF. However, neither of them were efficacious in predicting 30-day rehospitalization. The mean NT-proBNP values being: not rehospitalized (2114.7486) and 30 day rehospitalization (1008.42860) and the mean ST2 values being: not rehospitalized (336.1975), and 30-day rehospitalization. (281.9657). Conclusion: Neither ST2 or NT-proBNP was efficacious in predicting the short- term prognosis in HF with reduced EF. Both however were successful at confirming the diagnosis of HF in HF patients with reduced EF.

Bombesin Reduces Food Intake after a Preload in Man by a Cholecystokinin-Independent Mechanism

1993 ◽  
Vol 85 (3) ◽  
pp. 277-280 ◽  
Author(s):  
R. J. Lieverse ◽  
J. B. M. J. Jansen ◽  
A. A. M. Masclee ◽  
C. B. H. W. Lamers
Keyword(s):  
Food Intake ◽  
Receptor Antagonist ◽  
Healthy Subjects ◽  
Saline Infusion ◽  
Blind Study ◽  
Double Blind Study ◽  
Double Blind ◽  
Cholecystokinin Receptor ◽  
Independent Mechanism

1. A double-blind study was undertaken to determine whether the infusion of bombesin inhibits the intake of a carbohydrate-rich meal, consumed 15 min after a 300 ml banana shake, in nine lean healthy subjects and whether the possible inhibition of food intake by bombesin is mediated by cholecystokinin. 2. The amount of food eaten during infusion of bombesin (267 ±60 g) and bombesin combined with the cholecystokinin-receptor antagonist loxiglumide (269±39g) was slightly (P = 0.09) less than during saline infusion (384 ± 40 g). In addition, preprandial feelings of hunger were significantly less during infusion of both bombesin and bombesin combined with loxiglumide. 3. In conclusion, infusion of bombesin tends to inhibit the intake of a carbohydrate-rich meal after a preload by a cholecystokinin-independent mechanism.

scholarly journals Pharmacokinetics (PK) and Safety of Intravenous (IV) Brincidofovir (BCV) in Healthy Adult Subjects

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S311-S311 ◽  
Author(s):  
Mary Beth Wire ◽  
Marion Morrison ◽  
Maggie Anderson ◽  
Thangam Arumugham ◽  
John Dunn ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Geometric Mean ◽  
Compartmental Analysis ◽  
Repeat Dose ◽  
Double Blind Study ◽  
Double Blind ◽  
Dose Administration ◽  
To Receive ◽  
Male Subjects ◽  
Support Evaluation

Abstract Background BCV is a lipid conjugate nucleotide that has shown rapid viral clearance in patients with adenovirus infection and improved survival in animal models of smallpox. In preclinical studies in rats, IV BCV dosed twice weekly for up to 29 days was not associated with gastrointestinal (GI), hematopoietic, hepatic, or renal toxicity. This study evaluated the safety and PK of IV BCV in healthy subjects. Methods In this double-blind study, subjects were randomized 3:1 to receive IV BCV or placebo in sequential single ascending dose cohorts (Table 1). Plasma PK samples were collected over 7 days and assayed by HPLC-MS. Plasma BCV PK parameters were determined by non-compartmental analysis and dose proportionality was assessed. Safety assessments were collected over 14 days. Results Forty healthy male subjects (18–46 years, 83% White) were enrolled and completed the study. Plasma BCV Cmax and AUC∞ increased in proportion to dose (Table 1). AEs and alanine aminotransferase (ALT) elevations were dose- and infusion duration-related (Table 1). GI AEs were mild. All AEs and ALT elevations were transient and no serious AEs occurred. Conclusion Single doses of BCV 10–50 mg administered as a 2h IV infusion were well tolerated and not associated with significant clinical or laboratory abnormalities. BCV IV 10 mg and BCV IV 50 mg achieved geometric mean plasma BCV AUC∞ similar to and 4.5-fold, respectively, values achieved with BCV oral 100 mg tablets (Cmax = 251 ng/mL and AUC∞ = 1394 ng hours/mL). These data support evaluation of repeat dose administration in healthy subjects and virally-infected patients. Disclosures M. B. Wire, Chimerix: Employee and Shareholder, Salary. M. Morrison, Chimerix: Employee and Shareholder, Salary.M. Anderson, Chimerix: Employee and Shareholder, Salary. T. Arumugham, Chimerix: Employee and Shareholder, Salary. J. Dunn, Chimerix: Employee and Shareholder, Salary. O. Naderer, Chimerix: Employee and Shareholder, Salary.

Acetazolamide Reduces Referred Postoperative Pain after Laparoscopic Surgery with Carbon Dioxide Insufflation

2003 ◽  
Vol 99 (4) ◽  
pp. 924-928 ◽  
Author(s):  
Harvey J. Woehlck ◽  
Mary Otterson ◽  
Hyun Yun ◽  
Lois A. Connolly ◽  
Daniel Eastwood ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Laparoscopic Surgery ◽  
Carbonic Anhydrase ◽  
Carbonic Acid ◽  
Referred Pain ◽  
Double Blind Study ◽  
Carbon Dioxide Insufflation ◽  
Double Blind ◽  
Pain Scores ◽  
Incisional Pain

Background Carbon dioxide is the preferred insufflating gas for laparoscopy because of greater safety in the event of intravenous embolism, but it causes abdominal and referred pain. Acidification of the peritoneum by carbonic acid may be the major cause of pain from carbon dioxide insufflation. Carbonic anhydrase is an enzyme that increases the rate of carbonic acid formation from carbon dioxide. Because acetazolamide inhibits carbonic anhydrase, the authors hypothesized that the pain caused by carbon dioxide insufflation may be decreased by the administration of acetazolamide. Methods A prospective, randomized, double-blind study of 38 patients undergoing laparoscopic surgery during general anesthesia was performed. Acetazolamide (5 mg/kg) or a saline placebo was administered intravenously during surgery. Pain was rated on a visual analog scale (0-10) at four times: when first awake, at discharge from the recovery room, when discharged from the hospital, and on the day after surgery. The site and quality of pain were recorded, as were medications and side effects. Results Initial referred pain scores were lower after acetazolamide (1.00 +/- 1.98; n = 18) than after placebo (3.40 +/- 3.48; n = 20; P = 0.014), and 78% of patients in the acetazolamide group had no referred pain; however, only 45% patients in the placebo group had no referred pain. Incisional pain scores were not statistically different, and referred pain scores were similar at later times. Conclusions Acetazolamide reduces referred but not incisional pain after laparoscopic surgical procedures. The duration of pain reduction is limited to the immediate postsurgical period.

Effect of a Nitroglycerin Patch on Perfusion to the Foot in Healthy Subjects

2006 ◽  
Vol 96 (4) ◽  
pp. 318-322 ◽  
Author(s):  
Paul Jeong Kim ◽  
L. Clay Ballinger ◽  
Donald Kushner
Keyword(s):  
Nitric Oxide ◽  
Healthy Subjects ◽  
Healing Process ◽  
Experimental Period ◽  
Drug Group ◽  
Wound Healing Process ◽  
Double Blind Study ◽  
Double Blind ◽  
Adhesive Patch ◽  
The Subject

Nitric oxide is an endogenous gas released by endothelial cells that induces vasodilatation and plays other important roles in the wound-healing process. Nitroglycerin preparations are liberators of nitric oxide. Podiatric physicians have used nitroglycerin paste and patches on patients in an attempt to increase perfusion to the foot. However, the drug’s efficacy seems to be largely anecdotal. A prospective, randomized, placebo-controlled, double-blind study was conducted to investigate the efficacy of a nitroglycerin patch in locally increasing perfusion to the foot. Twenty-two healthy subjects were randomly assigned to either a drug group (nitroglycerin patch, 0.2 mg/h) or a placebo group (adhesive patch without active ingredient). The patch was applied to the plantar arch of the foot. Objective and subjective measures were then used to detect changes in perfusion to the foot after a 2-hour experimental period. The objective measures, cutaneous thermometry and photoplethysmography, found no significant measurable difference in perfusion to the foot between the drug and placebo groups (P > .05). A subjective questionnaire used to assess changes in temperature or sensation detected by the subject yielded similar results. Thus a nitroglycerin patch dose of 0.2 mg/h showed no measurable ability to increase perfusion to the foot. Further research is needed to validate the indications for this therapy. (J Am Podiatr Med Assoc 96(4): 318–322, 2006)

Sign in / Sign up

Export Citation Format

Share Document