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Biomedical subjects

B R Line

Publications and source records attributed to B R Line.

At least 37 records · Page 2Linked to original sources
PubMed1986

Acquisition of gamma camera and physiological data by computer.

We have designed, implemented, and tested a new Research Data Acquisition System (RDAS) that permits a general purpose digital computer to acquire signals from both gamma camera sources and physiological signal sources concurrently. This system overcomes the limited multi-source, high speed data acquisition capabilities found in most clinically oriented nuclear medicine computers. The RDAS can simultaneously input signals from up to four gamma camera sources with a throughput of 200 kHz per source and from up to eight physiological signal sources with an aggregate throughput of 50 kHz. Rigorous testing has found the RDAS to exhibit acceptable linearity and timing characteristics. In addition, flood images obtained by this system were compared with flood images acquired by a commercial nuclear medicine computer system. National Electrical Manufacturers Association performance standards of the flood images were found to be comparable.

Humans↗
PubMed1983

Cystic fibrosis related lung diseases in young adults with minimal impairment.

A small fraction of patients with cystic fibrosis (CF) survive to adulthood with exceptionally mild pulmonary impairment, in marked contrast to the usual natural history of CF. 6 young adults with CF with a high clinical score were studied to assess lung function, roentgenography, bacteriology, and the distribution of ventilation and perfusion. 1 such patient died during the course of the study from a cause other than CF-related respiratory failure, and the autopsy findings were reviewed. Although a few individuals showed normal and near-normal pulmonary function, evidence for mild to moderate obstructive airways disease was present in most tests performed, particularly the maximal expiratory flow between 25 and 75% of vital capacity. The helium dilution technique of determining total lung capacity generally underestimated the values by the technique of roentgenographic planimetry which were within the normal range. Lung scintigraphy revealed matched subsegmental defects in ventilation and perfusion, with 2 subjects showing mismatched defects. The histological findings in the deceased patient were similar to those in infants before the development of pulmonary infection and showed an abnormally thick and uneven basement membrane of the bronchial epithelium. These findings support the view that CF-related lung disease in these patients is qualitatively similar to the early disease in children, but is exceptionally slow to develop in a favored few who nonetheless have greater functional disturbance than their lack of symptoms would suggest.

Adult↗
PubMed1983

Effect of intermittent high dose parenteral corticosteroids on the alveolitis of idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal disorder in which chronic accumulation of neutrophils within the alveolar structures occurs. These cells with their large stores of preformed mediators likely play a major role in subsequent lung derangement. To evaluate the adjunctive use of intermittent high dose "pulse" corticosteroid therapy as a means of inhibiting neutrophil accumulation in the IPF lung, 5 patients were treated in a single blind random fashion with "high dose" corticosteroids (2 g methylprednisolone given intravenously once a week plus 0.25 mg/kg prednisone given orally daily) and 8 patients were treated with "low dose" corticosteroids only (0.25 mg/kg prednisone given orally daily). All patients had biopsy-proved disease in midcourse, and the 2 groups were matched for clinical and physiologic criteria. To evaluate the effect of these therapies on the quantity of neutrophils in the lungs of these patients, both groups underwent bronchoalveolar lavage and 67Ga scanning at the beginning and end of the 6-month study period; both methods gave an estimate of the intensity of the neutrophil alveolitis in these patients. Low dose corticosteroids had little effect on neutrophil accumulation (% neutrophils in lavage, - 5 +/- 8% change from baseline; 67Ga uptake, + 27 +/- 14% change from baseline), whereas high dose corticosteroids significantly reduced neutrophil accumulation (% neutrophils in lavage, - 46 +/- 8% change from baseline, p less than 0.02 compared with that in the low dose group; 67 Ga uptake, - 23 +/- 11% change from baseline, p less than 0.05 compared with that in the low dose group). In addition, 2 patients in the high dose group were reevaluated 6 months after cessation of the intermittent high dose pulse corticosteroids. Both had marked increases in lavage neutrophils compared with when they were receiving the high dose therapy (10 to 22% and 18 to 52%, respectively). These findings suggest that massive doses of intermittent intravenously administered corticosteroids may help to suppress the neutrophil component of the alveolitis of IPF.

Administration, Oral↗
PubMed1983

The alveolitis of pulmonary sarcoidosis. Evaluation of natural history and alveolitis-dependent changes in lung function.

Current concepts of the pathogenesis of pulmonary sarcoidosis suggest that a mononuclear cell alveolitis, comprised of activated T-lymphocytes and activated alveolar macrophages, precedes and modulates the formation of granuloma and fibrosis that characterize the disease. To evaluate the natural history of this alveolitis and determine the relationship it has to subsequent changes in lung function, 19 untreated patients with pulmonary sarcoidosis without extrapulmonary manifestations were studied at 6-month intervals over 10.1 +/- 1.6 months with bronchoalveolar lavage, 67Ga scanning, and pulmonary function tests to evaluate lung T-cells, lung alveolar macrophages, and lung function, respectively. In this group of patients with sarcoidosis, low intensity alveolitis (lung T-cells less than or equal to 28% of all lung effector cells and/or 67Ga scan negative) was much more common (80% of all observations) than high intensity alveolitis (lung T-cells greater than 28% and 67Ga scan positive, 20% of all observations). However, the alveolitis can be unstable; 75% of all episodes of high intensity alveolitis spontaneously reverted to low intensity, whereas 12% of all episodes of low intensity alveolitis spontaneously reverted to high intensity. Furthermore, conventional clinical, roentgenographic, or physiologic studies could not predict the alveolitis status; the low intensity and high intensity groups were indistinguishable by usual criteria (p greater than 0.3, all comparisons). Interestingly, of the 51 alveolitis evaluations in the 19 patients, there were 24 occurrences (47%) where the alveolitis was "split," i.e., 67Ga scans positive and T-cells low (39%) or 67Ga negative and T-cells high (8%). In fact, 79% of all patients had either a positive 67Ga scan and/or high lung T-cells at least once during the study period, suggesting that most untreated patients with sarcoidosis without extrapulmonary symptoms often have some inflammatory processes ongoing in their alveolar structures. Overall, whenever a high intensity alveolitis episode occurred, it was followed by deterioration over the next 6 months in at least one lung function parameter 87% of the time. In contrast, a low intensity alveolitis episode was followed by functional deterioration only 8% of the time. Strikingly, while the alveolitis parameters (lavage and 67Ga scanning) clearly predicted prognosis, clinical, roentgenographic, and physiologic tests could not distinguish those patients who would subsequently deteriorate functionally. These observations should prove useful in understanding the natural history of pulmonary sarcoidosis, in staging patients with this disease, and in making rational therapy decisions.

Adult↗
PubMed1982

Lung inflammation in sarcoidosis: comparison of serum angiotensin-converting enzyme levels with bronchoalveolar lavage and gallium-67 scanning assessment of the T lymphocyte alveolitis.

Serum angiotensin-converting enzyme (ACE) is elevated in many patients with pulmonary sarcoidosis and has been proposed as a measure of disease activity. The present study was designed to evaluate the possible relationship between serum ACE and direct measures of the intensity of the alveolitis of pulmonary sarcoidosis as measured by bronchoalveolar lavage and gallium-67 (67Ga) scans. To accomplish this, 64 measurements of serum ACE, lavage T lymphocytes, and lung uptake of 67Ga were performed in 41 patients with biopsy-proven sarcoidosis. Elevations of serum ACE were found on at least one occasion in 17 patients (41%). However, serum ACE was found to be a poor predictor of the intensity of alveolitis in sarcoidosis as assessed by the quantitation of bronchoalveolar lavage cells that were T lymphocytes and by 67Ga scanning. Elevated serum ACE did not predict which patients would have elevated proportions of lavage T lymphocytes, which patients would demonstrate increased pulmonary uptake of 67Ga, or which patients would have high-intensity alveolitis as defined by a combination of these criteria. These observations suggest that while serum ACE may be useful in diagnosing sarcoidosis, it does not reflect accurately the intensity of the alveolitis of the pulmonary component of this disease.

Adult↗
PubMed1982

Dirofilaria immitis. VI. Antimicrofilarial immunity in experimental filariasis.

Antimicrofilarial immunity was studied in Dirofilaria immitis-infected dogs in order to better understand amicrofilaremic filariasis in man. Sera from dogs with amicrofilaremic infections contained IgG antibodies specific for microfilarial surface antigens detectable by immunofluorescence and in vitro leukocyte adherence. In vivo immune mechanisms were studied by injecting 51Cr-labeled microfilariae (MF) into infected and uninfected dogs. Injected MF were concentrated in lung, liver, spleen, and kidneys of normal and microfilaremic dogs, but circulated throughout the 5-hour study period. In contrast, injected MF were rapidly cleared (15-30 min) from the blood of amicrofilaremic-infected dogs. Tissue radioactivity and histopathology indicated that injected MF were trapped and destroyed in the lungs of these dogs. Antibody-dependent clearance and destruction of MF is a potent anti-helminth effector mechanism in canine dirofilariasis. Similar events are likely to occur in amicrofilameric filariasis in humans.

Animals↗
PubMed1981

Deep venous thromboembolism in patients undergoing inguinal lymph node dissection for melanoma.

Deep venous thromboembolism (DVT) was studied in 44 patients with clinical Stage I, II, and III melanoma undergoing staging and therapeutic inguinal lymph node dissection. The ability of two noninvasive methods of surveillance, the phleborheograph (PRG) and the 125I fibrinogen scan to detect deep venous thrombosis was determined by comparison with prospective bilateral lower extremity venograms. In addition, the therapeutic impact, both beneficial and detrimental, of low dose heparin, 5000 units administered subcutaneously two hours prior to and every eight hours after operation was determined in a double blind study. The sensitivity of the PRG and 125I fibrinogen scan were both 20%. There were five deep venous thrombi, and two pulmonary emboli for a combined incidence of DVT of 13.6% for the entire patient population. However, there was no significant difference in the incidence of DVT between the two groups. The heparin-treated patients had an increased total volume (796 +/- 516 versus 388 +/- 208 ml; p less than 0.05), and duration of wound drainage (9 +/- 4 versus 13 +/- 6 days; p less than 0.05).

Bed Rest↗
PubMed1981

Gallium-67 scanning to stage the alveolitis of sarcoidosis: correlation with clinical studies, pulmonary function studies, and bronchoalveolar lavage.

Current concepts of the pathogenesis of sarcoidosis suggest that the alveolitis of this disorder is related to increased numbers of mononuclear phagocytes and activated T-lymphocytes within the lung. To determine if 67Ga scanning, a procedure commonly used in the evaluation of inflammation, would be useful in staging the alveolitis of sarcoidosis, we studied 41 patients with this disorder and correlated estimates of pulmonary 67Ga accumulation with clinical, roentgenographic, physiologic, and bronchoalveolar lavage studies in these patients. Although 65% of patients with sarcoidosis showed increased amounts of 67Ga accumulation in the lung compared with control subjects, only weak correlations (r less than +/- 0.42, all comparisons) were found between the degree of gallium uptake and the clinical, roentgenographic, or physiologic data. In contrast, there was a strong correlation of 67Ga uptake and the number of lymphocytes and T-lymphocytes recovered from the lungs of these patients by bronchoalveolar lavage (p less than 0.0001, r greater than or equal to 0.67, both comparisons). This data suggested that gallium uptake reflects the intensity of the T-lymphocytes mediated component of the alveolitis in sarcoidosis. Because 67Ga scans are noninvasive, simple to perform, and widely available, they should prove useful to stage the activity of sarcoidosis and to make decisions regarding therapy directed against the alveolitis of the disease.

Adult↗
PubMed1980

Chronic airflow obstruction in Fabry's disease.

Seven patients with Fabry's disease, an x-linked sphingolipid storage disorder, were evaluated for the presence and extent of airway obstruction. All were found to have significant obstruction to airflow. In addition, evaluation of their airway epithelial cells obtained by bronchoscopy demonstrated that these cells contained inclusion bodies consistent with deposits of ceramide trihexoside, suggesting that part of their functional obstruction to airflow may be secondary to intrinsic airway disease. Although all of the study population had evidence of airflow obstruction, the impairment was much worse in those who smoked, implying that even mild cigarette smoking is particularly hazardous to patients with Fabry's disease.

Adult↗
PubMed1980

Scintigraphic evaluation of regional pulmonary ventilation.

Radioactive gases are useful for evaluating pulmonary ventilation because they allow assessment of regional lung function in a physiologic, noninvasive manner. The most widely used radioactive gases are Xe-133, Xe-127, and Kr-81m. These gases provide visual and/or quantitative assessments of regional ventilation or ventilation-perfusion matching in obstructive airways disease, and aid the scintigraphic diagnosis of pulmonary embolism. The precision of ventilation scintigraphy is limited by detector resolution, signal distortion at depth, poor counting statistics, and respiratory motion.

Airway Obstruction↗
PubMed1980

Influence of triiodothyronine withdrawal time on 131I uptake postthyroidectomy for thyroid cancer.

Radioiodine uptake by thyroid remnants and metastases postthyroidectomy for thyroid cancer is increased by withdrawing thyroid hormone, which raises TSH levels. The minimal withdrawal time for maximal uptake is unknown. Therefore, we performed 33 studies in 27 patients after 2 weeks and again after 4 weeks of T3 withdrawal. We examined cervical (or pulmonary) uptake and whole body scanning at 48 h and whole body retention at 48, 72, and 96 h after radioiodine. In 4 studies, only physiological nonthyroidal activity was seen on both scans. Cervical uptake was low in these 4 studies. Of the remaining 29 studies with thyroid activity on both scans, 4 had high cervical uptakes after 2 weeks, which decreased by 4 weeks to less than 50% of the 2 week value. The same trend was seen in whole body retentions. In 2 studies, the uptake increased at 4 weeks compared to that at 2 weeks, but the change was small and was reflected in whole body retention of only 1 of these subjects. In 23 studies, including 6 with metastatic disease, the individual uptakes and whole body retentions were similar after 2 and 4 weeks. The mean uptakes and retentions also did not differ despite significantly higher (P less than 0.001) TSH values at 4 weeks. All definite areas of localization of radioactivity seen on the scans after 4 weeks were seen after 2 weeks. Therefore, radioiodine uptake, scanning, and therapy should be performed after 2 weeks of T3 withdrawal when patients are minimally hypothyroid. Serum TSH should also be measured to identify the rare individual not responding to brief T3 withdrawal.

Adolescent↗
PubMed1980

Radionuclide cinepneumography: flow-volume imaging of the respiratory cycle.

A procedure is described that generates a series of images spanning an average respiratory cycle. Images are constructed from scintigraphic data with similar respiratory flow and volume characteristics so that they may be displayed in continuous-loop movie format. This technique is noninvasive and requires little patient cooperation or technologist time. It should be most useful in investigations of dynamic pulmonary function, but may be applied to any radionuclide study affected by respiratory motion.

Humans↗
PubMed1979

Regional ventilatory clearance by xenon scintigraphy: a critical evaluation of two estimation procedures.

Estimates of ventilatory clearance are usually made by inspecting xenon washout images. Quantitative computer procedures have been described that produce regional clearance rates, yet their accuracy is not well established. We define a mathematical model for scintigraphic ventilation data based on 96 clinical studies, and with this model we test the accuracy of two procedures used to estimate ventilatory clearance. The least-squares curve-fitting technique for both washin and washout data has the same accuracy as a modified Stewart-Hamilton method (A/H) that uses washout data alone. Both procedures demonstrate relative errors of less than 5% and coefficients of variation of 10-20% when regions with equilibrium count rates of 3 cps and clearance times between 10 and 90 sec are examined. Because the A/H procedure is preferred for its simplicity and speed, we analyze two of its main sources of error: early washin/washout termination and background activity. To measure regional ventilation by the A/H procedure, we recommend: (a) washin and washout periods at least three times the largest clearance time of clinical interest; b) a regional equilibrium count rate of at least 3cps; and c) a 25- to 50-sec average of the equilibrium count rate.

Humans↗