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Biomedical subjects

B J Shapiro

Publications and source records attributed to B J Shapiro.

At least 19 recordsLinked to original sources
PubMed1991

Mediastinal masses: magnetic resonance imaging in comparison with computed tomography.

Seventy-eight patients with mediastinal abnormalities were imaged with magnetic resonance imaging (MRI) to evaluate mediastinal masses and associated lung, pleural, or chest wall disease. Magnetic resonance images were compared with computed tomography (CT) scans, which were available in 45 patients. While MRI and CT were equally effective in demonstrating mediastinal lesions, CT was superior for displaying calcification within a mass in eight patients and for demonstrating associated lung abnormality in four patients. Computed tomography should remain the imaging procedure of choice after chest radiography to evaluate mediastinal masses, although MRI may be indicated in selected patients.

Adolescent↗
PubMed1986

Sensitivity and specificity of first screen mammography in the Canadian National Breast Screening Study: a preliminary report from five centers.

Sensitivity and specificity of first screen mammography in a randomized screening trial at five centers are reported. A total of 23,101 women underwent mammography; in 139, breast cancer was detected at first screening; in 20, less than 12 months after first screening; and in 47, at second screening. All 206 cancer cases were histologically confirmed, and 174 were defined as being detectable at first screening. Average length of follow-up for all women was 3.2 years. Interpretations of first screen mammograms by the center radiologists were matched to known outcomes. Simultaneous blind review was performed by a single reference radiologist with mammograms from all 206 cancer cases and those of a random sample of 739 women not known to have breast cancer at 15 months or more after initial screening. Overall, the five screening centers achieved a sensitivity of 69% (range, 60%-78%), a specificity of 94% (range, 93%-96%), a positive predictive value of 8.6% (range, 3%-16%), and a negative predictive value of 99.7% (range, 99.6%-99.9%).

Breast Neoplasms↗
PubMed1985

Conservation of oxygen supply using a reservoir nasal cannula in hypoxemic patients at rest and during exercise.

A reservoir nasal cannula which stores oxygen during exhalation and delivers it as a bolus during inhalation has been reported to conserve oxygen delivery in patients with chronic obstructive pulmonary disease (COPD) at rest. We compared the effects upon arterial oxygen saturation (SaO2) of the reservoir cannula and a standard nasal cannula in hypoxemic obstructed and restricted patients at rest and during exercise. The SaO2 was monitored by ear oximeter. While at rest, 13 obstructed and four restricted patients breathed oxygen from the reservoir cannula at 0.5, 1.0, 1.5, and 2.0 L/min and from a standard cannula at 0.5, 1.0, 2.0, 3.0, and 4.0 L/min. Mean SaO2 was significantly higher with the reservoir cannula compared to the standard cannula at 1.0 and 2.0 L/min (p less than 0.0006) and tended to be higher at 0.5 L/min (p less than 0.1). Seven obstructed patients walked on a level treadmill at 0.75 mph while breathing oxygen at 0.5 and 1.5 L/min from the reservoir cannula and at 1.0 and 3.0 L/min from the standard cannula. The SaO2 during exercise with the reservoir cannula was comparable to that with the standard cannula at approximately half of the oxygen flow rate. The ratio of the oxygen flow rate of the standard to the reservoir cannula to produce 90 percent saturation was estimated and found to be 2.5 +/- 0.8 (mean +/- SD) for patients at rest and 2.9 +/- 1.8 during exercise. We conclude that in hypoxemic patients at rest and during exercise, the reservoir cannula uses less than half the oxygen of a standard cannula to produce similar improvement in SaO2 and thus has advantages of a reduced cost of ambulatory therapy with low-flow oxygen and a longer time permitted away from a stationary source of oxygen.

Carbon Dioxide↗
PubMed1984

Acute and subacute bronchial effects of oral cannabinoids.

The bronchodilating activity of oral cannabinoids was evaluated in three double-blind experiments that involved the study of dose-response and interactive relationships and the potential development of tolerance. Data indicated that delta 8-tetrahydrocannabinol (delta 8-THC), cannabinol (CBN), and cannabidiol (CBD) in maximal doses of 75 mg, 1200 mg, and 1200 mg, respectively, did not induce significant dose-related physiologic effects in experienced marijuana smokers. delta 8-THC (75 mg) was, however, associated with bronchodilation, tachycardia, and peak highs less than that after delta 9-tetrahydrocannabinol (delta 9-THC). The combinations of CBN and CBD with low-dose delta 9-THC (5 mg) did not induce significant bronchodilation but did exert interactive effects on heart rate and "high." A 20-day study of daily delta 9-THC (20 mg), CBN (600 mg), and CBD (1200 mg) did not indicate tolerance or reverse tolerance to any drug. We conclude that delta 9-THC and, to a lesser extent, delta 8-THC, have acute bronchodilator activity but that CBN, CBD, and their combinations do not provide effective bronchodilation. The daily use of delta 9-THC was not associated with clinical tolerance.

Administration, Oral↗
PubMed1984

The IPPB trial.

Explore the source record for details and available documents.

Aerosols↗
PubMed1980

Methods of intermittent positive pressure breathing.

Inspiratory capacity (IC) was evaluated in 60 patients during the following four respiratory maneuvers: (1) coached unassisted inspiration; (2) inspiratory positive-pressure breathing (IPPB) at 15 cm H2O with the patient passively inspiring; (3) IPPB at 15 cm H2O with the patient coached to actively inspire; and (4) IPPB at a peak pressure adjusted according to the judgment of the respiratory therapist, with the patient coached to actively inspire. The IC attained with these maneuvers were, respectively, as follows: (1) 1.29 +/- 0.75 L; (2) 1.13 +/- 0.52 L; (3) 1.77 +/- 0.11 L; and (4) 2.27 +/- 0.11 L (mean +/- SE). The peak ventilator pressure for maneuver 4 averaged 30 +/- 7 cm H2O (mean +/- SD), and no patient experienced harmful side effects from these peak pressures. These data indicate that the method of treatment with IPPB has profound effects upon the degree of pulmonary expansion. All research on therapy with IPPB should be carefully controlled for the method of administering IPPB, and the volumes obtained during the treatment should be carefully documented before general conclusions are drawn concerning the effects of IPPB on morbidity. For the present, we suggest that IPPB, when administered clinically, be given as described in method 4.

Adult↗
PubMed1980

Respiratory status of seventy-four habitual marijuana smokers.

Previous studies of the long-term effects of habitual marijuana smoking on respiratory status and lung function have yielded conflicting results. In the present study, lung function tests obtained in 74 regular marijuana smokers (duration of smoking > two-five years; frequency of smoking three days/week to several times/day) who denied intravenous narcotic drug abuse were compared with similar tests performed in two groups of control subjects. One group consisted of individuals tested in a mobile laboratory who were computer-matched to the marijuana smokers for anthropometric characteristics and quantity and duration of tobacco smoking; the other group was comprised of 41 nonsmokers of marijuana who were tested in the same laboratory as the marijuana smokers. Paired and unpaired t analyses revealed lower values for specific airway conductance (-0.07 to -0.08 +/- 0.02; P < 0.001) in the marijuana smokers compared with either group of control subjects, but no differences in spirometric indices, closing volume or delta N2 750-1250. When non-tobacco smoking marijuana users (n = 50) were matched with either non-tobacco smoking or tobacco smoking control subjects, significant differences were again noted in specific airway conductance (P < 0.001) but not in spirometric tests, closing volume or delta N2 750-1250. These results suggest that habitual smoking of marijuana may cause mild, but significant, functional impairment predominantly involving large airways which is not detectable in individuals of the same age who regularly smoke tobacco. The clinical implications of these findings await further study.

Adult↗
PubMed1980

Familial Warthin's tumor. 1. Its synchronous occurrence in mother and son. 2. Its association with cystic oncocytic metaplasia of the larynx.

Warthin's tumor of the parotid gland is an unusual tumor for which a number of theories of pathogenesis have been advanced through the years, ranging from a branchiogenic origin to an embryonic lymph node origin to true neoplasia from parotid epithelial duct cells. Recently Allegra has suggested that Warthin's tumor may be a hypersensitivity disease. Presented here are two unique cases of Warthin's tumor, having both a familial relationship (synchronous occurrence in mother and son) and the association with cystic oncocytic metaplasia of the larynx. Observations lead to the conclusion that the lesion is primarily metaplastic, not neoplastic, with a secondary lymphoid reaction of the delayed hypersensitivity type.

Adenolymphoma↗
PubMed1978

Do static cystourethrograms have a role in the investigation of female incontinence?

Two hundred and forty-eight women with lower urinary tract complaints who were referred to a special gynecologic urology and urodynamic unit had static cystourethograms (CUG's) performed as part of their diagnostic workups. In women with urodynamic evidence of true anatomic sphincter-weakness stress urinary incontinence (SUI), there was a poor correlation with standard CUG interpretations of SUI as suggested by Green (Types I and II). Also, pure SUI was rarely seen as the sole problem and most patients demonstrated combinations of sensory urgency and unstable bladders. With the recent advent of more formal techniques of urodynamic investigation to include cystoscopy, urethroscopy, and simultaneous cyctometry and urethral pressure profilometry, the importance of a more thorough investigation of lower urinary tract complaints prior to surgical intervention is emphasized.

Adolescent↗
PubMed1977

Bronchial effects of aerosolized delta 9-tetrahydrocannabinol in healthy and asthmatic subjects.

Effects on airway dynamics, heart rate, and the central nervous system of various doses of delta9-tetrahydrocannabinol administered in a random, double blind fashion using a Freon-propelled, metered-dose nebulizer were evaluated in 11 healthy men and 5 asthmatic subjects. Effects of aerosolized delta9-tetrahydrocannabinol were compared with aerosolized placebo and isoproterenol and with 20 mg of oral and smoked delta9-tetrahydrocannabinol. In the normal subjects, after 5 to 20 mg of aerosolized delta9-tetrahydrocannabinol, specific airway conductance increased immediately, reached a maximum (33 to 41 per cent increase) after 1 to 2 hours, and remained significantly greater than placebo values for 2 to 3 hours. The bronchodilator effect of aerosolized delta9-tetrahydrocannabinol was less than that of isoproterenol after 5 min, but significantly greater than that of isoproterenol after 1 to 3 hours. The magnitude of bronchodilatation after all doses of aerosolized delta9-tetrahydrocannabinol was comparable, but 5 mg of delta9-tetrahydrocannabinol caused a significantly smaller increase in heart rate and level of intoxication than the 20-mg dose. Smoked delta9-tetrahydrocannabinol produced greater cardiac and intoxicating effects than either aerosolized or oral delta9-tetrahydrocannabinol. Side effects of aerosolized delta9-tetrahydrocannabinol included slight cough and/or chest discomfort in 3 of the 11 normal subjects. Aerosolized delta9-tetrahydrocannabinol caused significant bronchodilatation in 3 of 5 asthmatic subjects, but caused moderate to severe bronchoconstriction associated with cough and chest discomfort in the other 2. These findings indicate that aerosolized delat9-tetrahydrocannabinol, although capable of causing significant bronchodilatation with minimal systemic side effects, has a local irritating effect on the airways, which may make it unsuitable for therapeutic use.

Adult↗
PubMed1977

Short-term effects of smoked marihuana on left ventricular function in man.

The short-term effects of smoking one to three marihuana cigarettes (900 mg of marihuana per cigarette; 2.2% delta9-tetrahydrocannabinol) on left ventricular performance were evaluated in 21 experienced users of cannabis at different times during a 94-day in-hospital study of the biologic effect of daily heavy smoking of marihuana. In six subjects, cardiac output was determined using the indocyanine-green dye-dilution technique; and in two of these individuals and 15 additional subjects, cardiac output, ejection fraction, preejection period (PEP), left ventricular ejection time (LVET), and the velocity of circumferential fiber shortening (Vcf) were determined using echocardiograms, phonocardiograms, and carotid pulse recordings. Following the smoking of one to three marihuana cigarettes, the heart rate rose 16 to 53 percent, cardiac output rose 4 to 9 percent, stroke volume did not change or fell slightly, and ejection fraction, PEP/LVET, and did not change, except for a slight increase in Vcf (15%) after three marihuana cigarettes, which could be accounted for by the associated increase in heart rate (53%). These findings suggest that in long-term heavy users of cannabis, marihuana has no significant effect on myocardial contractility independent of its effect on heart rate.

Adult↗
PubMed1976

Subacute effects of heavy marihuana smoking on pulmonary function in healthy men.

To evaluate the subacute effects of heavy marihuana smoking on the lung, pulmonary function was tested in 28 healthy young male experienced cannabis users, before and after 47 to 59 days of daily ad-libitum marihuana smoking (mean of 5.2 marihuana cigarettes per day per subject, 2.2 per cent delta9-tetrahydrocannabinol). Base-line pulmonary-function studies were nearly all within normal limits, but after 47 to 59 days of heavy smoking, statistically significant decreases in forced expired volume in one second (3 +/- 1 per cent, S.E.), maximal mid-expiratory flow rate (11 +/- 2 per cent), plethysmographic specific airway conductance (16 +/- 2 per cent) and diffusing capacity (8 +/- 2 per cent) were noted as compared with the base-line studies. The decreases in maximal mid-expiratory flow rate and specific airway conductance were correlated with the quantity of marihuana smoked. These findings suggest that customary social use of marihuana may not result in detectable functional respiratory impairment in healthy young men, whereas very heavy marihuana smoking for six to eight weeks causes mild but statistically significant airway obstruction.

Adult↗