Modulation of bronchial epithelial cell barrier function by in vitro jet propulsion fuel 8 exposure.
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The loss of epithelial barrier integrity in bronchial and bronchiolar airways may be an initiating factor in the observed onset of toxicant-induced lung injuries. Acute 1-h inhalation exposures to aerosolized jet propulsion fuel 8 (JP-8) have been shown to induce cellular and morphological indications of pulmonary toxicity that was associated with increased respiratory permeability to 99mTc-DTPA. To address the hypothesis that JP-8 jet fuel-induced lung injury is initiated through a disruption in the airway epithelial barrier function, paracellular mannitol flux of BEAS-2B human bronchial epithelial cells was measured. Incubation of confluent cell cultures with non-cytotoxic concentrations of JP-8 or n-tetradecane (C14), a primary constituent of JP-8, for a 1-h exposure period resulted in dose-dependent increases of paracellular flux. Following exposures of 0.17, 0.33, 0.50, or 0.67 mg/ml, mannitol flux increased above vehicle controls by 10, 14, 29, and 52%, respectively, during a 2-h incubation period immediately after each JP-8 exposure. C14 caused greater mannitol flux increases of 37, 42, 63, and 78%, respectively, following identical exposure conditions. The effect on transepithelial mannitol flux reached a maximum at 12 h and spontaneously reversed to control values over a 48-h recovery period, for both JP-8 and C14 exposure. These data indicate that non-cytotoxic exposures to JP-8 or C14 exert a noxious effect on bronchial epithelial barrier function that may preclude pathological lung injury. (+info)
Preoperative assessment of residual hepatic functional reserve using 99mTc-DTPA-galactosyl-human serum albumin dynamic SPECT.
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Preoperative assessment of residual hepatic functional reserve offers important strategic information for hepatic resection. To predict the postoperative residual liver function, we assessed the value of hepatic 99mTc-diethylenetriamine pentaacetic acid-galactosyl-human serum albumin (99mTc-GSA) clearance estimated by dynamic SPECT analysis. METHODS: We investigated 114 consecutive patients with liver disease, including 55 hepatectomy cases. One minute after injection of 185 MBq 99mTc-GSA, 15 serial dynamic SPECT images were obtained every minute. The initial five sets of SPECT images were analyzed by Patlak plot to estimate the sequential initial hepatic 99mTc-GSA clearance (mL/min) as an index of hepatic function. The sum of hepatic 99mTc-GSA clearance of the segments immune from resection was categorized as predicted residual 99mTC-GSA clearance. In the hepatectomy cases, scintigraphy was performed before and 37 +/- 10 d after the operation. RESULTS: Good correlation was observed between the total hepatic 99mTc-GSA clearance and conventional hepatic function tests: plasma retention rate of iodocyanine green (ICG) at 15 min (ICG R15), r = -0.600, P < 0.0001, n = 94; plasma disappearance rate of ICG (K ICG), r = 0.670, P < 0.0001, n = 83; cholinesterase, r = 0.539, P < 0.0001, n = 121; serum albumin, r = 0.421, P = 0.0001, n = 123; and hepaplastin test, r = 0.456, P < 0.0001, n = 120. There was good correlation between the predicted residual 99mTc-GSA clearance and the postoperative total hepatic 99mTc-GSA clearance in patients who underwent segmentectomy or lobectomy (r = 0.84, P < 0.0001, n = 28) and between the pre- and postoperative total hepatic 99mTc-GSA clearance in patients who underwent subsegmentectomy (r = 0.91, P < 0.0001, n = 25). Five patients who had postoperative complications due to hepatic insufficiency (2 patients died of postoperative hepatic failure within 2 mo after operation) showed significantly lower predicted residual 99mTc-GSA clearance compared with the patients without complications (90.3 +/- 37.2 versus 320.9 +/- 158.8 mL/min; P < 0.005). CONCLUSION: The total hepatic 99mTC-GSA clearance reflected hepatic function. In addition, preoperative predicted residual hepatic 99mTc-GSA clearance was a good indicator of postoperative hepatic function and early prognosis. 99mTc-GSA dynamic SPECT is assumed to be a useful method for determining the surgical strategy in patients with hepatic tumor and especially in patients with hepatic dysfunction. (+info)
Clinical usefulness of scintigraphy with 99mTc-galactosyl-human serum albumin for prognosis of cirrhosis of the liver.
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Scintigraphy with 99mTc-diethylenetriamine pentaacetic acid-galactosyl-human serum albumin (99mTc-GSA) is useful for evaluating hepatic functional reserve. We assessed the clinical usefulness of this technique, including its value in establishing a prognosis, in patients with cirrhosis of the liver. METHODS: Scintigraphy with 99mTc-GSA was performed in 10 healthy subjects, 42 patients with chronic hepatitis and 158 patients with cirrhosis. Computer acquisition of gamma camera data were started just before the injection of 99mTc-GSA. Time-activity curves for the heart and liver were generated from regions of interest (ROIs) for the heart and the entire liver. A receptor index was calculated by dividing the radioactivity of the liver ROI by that of the liver-plus-heart ROI 15 min after the injection. An index of blood clearance was calculated by dividing the radioactivity of the heart ROI at 15 min by that of the heart ROI at 3 min. RESULTS: The median receptor index was lower in patients with cirrhosis than in patients with chronic hepatitis or in healthy subjects, and the median index of blood clearance was higher. The receptor index was significantly lower when a complication (varices, ascites) was present. The index of blood clearance was significantly higher when a complication (varices and ascites) was present. Correlation of the two indices with classic indicators for functional reserve was significant. On the basis of the receptor index, the patients with cirrhosis were divided into two groups of roughly equal size: group A, receptor index over 0.85, and group B, receptor index 0.85 or less. On the basis of the index of blood clearance, the patients with cirrhosis were divided into two groups of roughly equal size: group A, index of blood clearance < 0.70, and group B, index of blood clearance > or = 0.70. The cumulative survival rates were lower in group B than in group A. CONCLUSION: Scintigraphy with 99mTc-GSA is clinically useful, especially in establishing the prognosis of patients with cirrhosis of the liver. (+info)
Detecting alveolar epithelial injury following volatile anesthetics by (99m)Tc DTPA radioaerosol inhalation lung scan.
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BACKGROUND: Many volatile anesthetics have long been thought to affect alveolar epithelial permeability. OBJECTIVE: The purpose of this study was to examine the acute effects of volatile anesthetics on the permeability of the alveolocapillary barrier to (99m)Tc DTPA. METHODS: Twenty-seven patients (24 females, 3 males, age 29-73 years) undergoing operation were enrolled in this study and grouped according to the type of anesthesia received. Group 1 patients were administered 1% halothane. Group 2 patients were given 1.5% isoflurane. Intravenous anesthesia without volatile anesthetics were used for group 3 patients. Before and after anesthesia, (99m)Tc DTPA radioaerosol inhalation lung scans were performed to detect alveolar epithelial injury due to volatile anesthetics. The negative slope of the regression line was designated as the (99m)Tc DTPA pulmonary clearance rate and was expressed in terms of percentage decrease in radioactivity per minute. RESULTS: In group 1, the (99m)Tc DTPA clearance rates were 1.26 +/- 0.34 and 1.29 +/- 0.38 before and after anesthesia, respectively. The difference was not significant (p > 0.05). In group 2, the rates were 0.76 +/- 0.20 and 1.10 +/- 0. 37, before and after anesthesia, respectively. The difference was significant (p < 0.05). In group 3, the clearance rates were 1.07 +/- 0.38 and 1.21 +/- 0.48, before and after anesthesia, respectively. The difference was not significant. CONCLUSIONS: Following isoflurane administration, the more rapid pulmonary clearance of (99m)Tc DTPA indicates that isoflurane increases the permeability of the alveolo-capillary barrier. (+info)
Studies of in vivo electropermeabilization by gamma camera measurements of (99m)Tc-DTPA.
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A protocol was developed to study the drug uptake from in vivo electropermeabilization at different settings of parameters influencing the uptake efficiency. Radiolabelled diethylenetriaminepentaacetic acid (DTPA) was used to trace the distribution and internalization of a hydrophilic drug after in vivo electropermeabilization. Skeletal muscle tissue in rat was treated with permeabilizing electric pulses before or after intravenous administration of (99m)Tc-DTPA. The drug accumulation in the treated volume was subsequently evaluated with a scintillation camera. The dependence of uptake on field strength and duration of the applied electric pulses was investigated for exponentially decaying pulses and square wave pulses. Further, the uptake dependence on time interval between injection and pulsation was studied as well as the uptake dependence on the number of pulses applied in a single electropermeabilization treatment. Dynamic gamma camera studies were performed to quantify the time scale of the drug uptake in electropermeabilized tissue. (+info)
Reverse mismatched ventilation-perfusion pulmonary imaging with accumulation of technetium-99m-DTPA in a mucous plug in a main bronchus: a case report.
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The phenomenon of reverse mismatched ventilation-perfusion on pulmonary scintigraphy is a fairly common occurrence. We present a patient who was experiencing decreasing oxygen saturation and had a reverse mismatched ventilation-perfusion imaging pattern associated with radiotracer retention in a main bronchus. Technetium-99m-DTPA aerosol lung imaging showed tracer retention in the trachea and right main bronchus, absent ventilation in the right lung, and normal ventilation in the left lung. Technetium-99m-MAA perfusion lung images showed normal perfusion of the left lung and some perfusion in the right lung. These findings represented a reverse ventilation-perfusion mismatch. Reverse mismatched ventilation-perfusion, or totally absent ventilation with preservation of some perfusion in the right lung, resulted in functional intrapulmonary shunting, which explained the decreasing oxygen saturation observed in this patient. A concurrent portable chest radiograph showed elevation of the right hemidiaphragm, a shift of the mediastinum to the right, deviation of the endotracheal tube, narrowing of the intercostal space of the right thorax, and collapse of the right lower lobe. The radiographic findings of underventilation of the right lung with atelectasis of the right lower lobe were due to mucous plugging the right main bronchus. (+info)
Response to percutaneous transhepatic portal embolization: new proposed parameters by 99mTc-GSA SPECT and their usefulness in prognostic estimation after hepatectomy.
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Accumulation of 99mTc-galactosyl human serum albumin (GSA) in the liver correlates well with the parameters of hepatic function tests. We performed 99mTC-GSA SPECT before and after percutaneous transhepatic portal embolization (PTPE) to induce compensatory hypertrophy of the remnant lobe before extensive hepatic resection and analyzed the responses of new proposed parameters in the future remnant lobe that showed hypertrophy. The aim of this study was to evaluate the usefulness of these parameters in prognostic estimation after hepatectomy. METHODS: We studied 10 patients with cholangiocarcinoma and 1 patient with metastatic liver tumor from sigmoid colon cancer. 99mTc-GSA SPECT was performed immediately before and 2 wk after PTPE. We analyzed the responses of the liver uptake ratio (LUR), functional volume (FV), and liver uptake density (LUD) in the future remnant lobe and evaluated their relationship with the prognosis after subsequent hepatic resection. RESULTS: LUR and FV increased slightly but were not associated with the prognosis after hepatic resection. LUD increased significantly after PTPE in the group showing a good outcome after hepatic resection but decreased after PTPE in the group showing a poor outcome (post-PTPE LUD, 0.064+/-0.017%/cm3 versus 0.035+/-0.006%/ cm3, P<0.05; response rate, 22.2%+/-11.9% versus -8.9%+/-17.6%, P<0.01). CONCLUSION: Responses of LUD to PTPE before hepatic resection in the future remnant lobe represent changes in asialoglycoprotein receptor activity per hepatocyte and predict responses to subsequent hepatic resection. LUD may be an important parameter for determining the outcome after hepatic resection. (+info)
Riedel's lobe of the liver evaluated by multiple imaging modalities.
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An 81-year-old Japanese woman visited our hospital because of abdominal discomfort. Physical examination revealed that she had an abdominal mass. A combination of ultrasonography, computed tomography, magnetic resonance imaging (MRI), and hepatic asialoglycoprotein scintigraphy was utilized to make a diagnosis. We found that she had a downward elongated hepatic lobe or Riedel's lobe which did not appear to be common in our district. The prevalence of Riedel's lobe in the Asian population has not been studied. Furthermore, this is the first report that describes the MRI and hepatic asialoglycoprotein scintigraphy features of Riedel's lobe of the liver. (+info)