Stereo-dependent inhibition of human platelet function by the optical isomers of trimetoquinol.
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15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
Biomedical subjects
J R Mayo
Publications and source records attributed to J R Mayo.
Synthesis, beta-adrenergic activity, and platelet antiaggregatory activity of a positional isomer of trimetoquinol: 1-(2',4',5'-trimethoxybenzyl)-6,7-dihydroxy-1,2,3,4,-tetrahydroisoquinoline.
A positional isomer of trimetoquinol (1), 1-(2',4',5'-trimethoxybenzyl)-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (3), was synthesized and found to possess less beta-adrenergic activity than 1 in isolated guinea pig atrial and tracheal preparations. The analogue 3 was an effective antiaggregatory agent in human and rabbit platelet-rich plasma preparations, while 1 was effective only as an inhibitor of arachidonic acid induced aggregation in human platelets. These findings indicate that both qualitative and quantitative differences in biological activity have occurred as a result of changing the position of the methoxy groups on the 1-benzyl substituent of 1.
Adrenergic beta-Agonists↗
Transfemoral liver biopsy by forceps: a review of 104 consecutive procedures.
PURPOSE: Transvenous liver biopsy is performed on patients with contraindications to percutaneous biopsy. Transfemoral liver biopsy has not been widely reported, and we present our experience of 104 consecutive procedures. METHODS: During a 30-month period, 88 patients underwent 104 transfemoral liver biopsies. Under fluoroscopic guidance a 9 Fr curved introducer catheter is passed into the right hepatic vein via a standard femoral sheath. A 7 Fr biopsy forceps is then passed into the liver, opened and wedged. Prior to biopsy, the image intensifer is rotated so the relation of the capsular surface to the biopsy site is verified and capsular perforation avoided. RESULTS: Tissue samples obtained in 97 of 104 procedures (93%) were adequate for diagnosis in 83 (80%). Complications occurred in six procedures (6%) including two capsular perforations; the latter two were treated by coil embolization. CONCLUSION: We found transfemoral liver biopsy using forceps to be a safe, well-tolerated procedure with a high diagnostic yield and it is a technically easy alternative to the transjugular approach using large needles.
Adolescent↗
MR imaging of double outlet right ventricle.
Five patients with angiographically proven diagnosis of double outlet right ventricle (DORV) were studied with magnetic resonance (MR) imaging. Magnetic resonance was compared with angiography and echocardiography. Contiguous electrocardiographic-gated spin-echo images were acquired on a 0.35 T imager. Magnetic resonance was equivalent to echocardiography in demonstrating relative relationships of the great arteries with respect to each other, the relative positions of the great arteries with respect to the ventricular septal defect (VSD), and the caliber of the great vessels. It was comparable in visualization of the size and position of the VSD and position of the atrioventricular valves. Due to limited spatial resolution, MR failed to identify chordal straddle of a tricuspid valve and incorrectly interpreted pulmonary stenosis as pulmonary atresia. A small patch leak of an internal baffle was only visualized on angiography. We conclude that MR is superior to echocardiography in the noninvasive assessment of the spatial arrangement and caliber of the great vessels. As such, it is a useful adjunct to echocardiography in the noninvasive assessment of DORV.
Adult↗
MRI of infiltrative lung disease: comparison with pathologic findings.
OBJECTIVE: Our goal was to compare MRI with pathologic findings in patients with chronic infiltrative lung disease. MATERIALS AND METHODS: The study included 22 consecutive patients who had MRI and lung biopsy performed within 21 days (median 4 days). Fifteen patients had open lung biopsy: five with idiopathic pulmonary fibrosis, three with extrinsic allergic alveolitis, and seven with miscellaneous conditions. Seven patients had transbronchial biopsy: four with sarcoidosis and three with miscellaneous conditions. All patients had 1.5 T MRI with cardiac-gated T1-, proton density-, and T2-weighted SE sequences. RESULTS: The predominant patterns of abnormality seen on MR included parenchymal opacification (n = 12), parenchymal opacification and reticulation (n = 2), reticulation (n = 3), nodularity (n = 3), and interlobular septal thickening (n = 1); normal findings were found in 1. The 14 patients with parenchymal opacification included 9 with ground-glass intensity and 5 with consolidation. In 12 of these 14 patients the parenchymal opacification represented an active inflammatory process including alveolitis, pneumonia, and granulomatous inflammation, while in 2 patients it represented fibrosis. Reticulation was shown to represent fibrosis in five of five cases. The three patients with nodules had sarcoidosis. CONCLUSION: The MR findings correlate closely with those seen on lung biopsy. Parenchymal opacification on MR usually indicates the presence of potentially reversible disease, while reticulation usually indicates irreversible fibrosis.
Adult↗
Diffuse pulmonary lymphangiomatosis: CT findings.
OBJECTIVE: Our objective was to determine and report the CT findings in patients with diffuse pulmonary lymphangiomatosis (DPL). MATERIALS AND METHODS: We retrospectively reviewed the CT findings in eight patients with pathologically proven DPL. The patients ranged in age from 3 to 35 years (mean 15 years) and included four male and four female patients. The CT scans were analyzed for type of pulmonary infiltrative process and its distribution, presence or absence of pleural fluid or thickening, and presence or absence of thoracic lymphadenopathy. RESULTS: The main abnormality seen on conventional and high resolution CT in all patients was smooth thickening of the interlobular septa and bronchovascular bundles. Seven of eight patients had patchy bilateral areas of ground-glass attenuation. All eight patients had diffuse increased attenuation of the mediastinal fat, approximating that of water, and mild bilateral perihilar infiltration. Seven of the eight had bilateral pleural effusions or smooth thickening of the pleura (or both), and two had regions of calcified pleural thickening. CONCLUSION: The constellation of CT features of DPL is distinctive and includes diffuse, smooth thickening of interlobular septa and bronchovascular bundles with extensive infiltration of the mediastinal fat and associated perihilar infiltration. Since the CT findings described are suggestive but not pathognomonic, definitive diagnosis requires lung biopsy.
Adolescent↗
Scintigraphic and MR perfusion imaging in preoperative evaluation for lung volume reduction surgery: pilot study results.
PURPOSE: To compare MR perfusion imaging with perfusion scintigraphy in the evaluation of patients with pulmonary emphysema being considered for lung volume reduction surgery. PATIENTS AND METHODS: Six patients with pulmonary emphysema and two normal individuals were evaluated by MR perfusion imaging, perfusion scintigraphy, and selective bilateral pulmonary angiography. MR images were obtained with an enhanced fast gradient recalled echo with three-dimensional Fourier transformation technique (efgre 3D) (6.3/1.3; flip angle, 30 degrees; field of view, 45-48 cm; matrix, 256 x 160). The presence or absence of perfusion defects in each segment was evaluated by two independent observers. RESULTS: Using angiography as the gold standard, the sensitivity, specificity, and accuracy of MR perfusion imaging in detecting focal perfusion abnormalities were 90%, 87%, and 89%, respectively, while those of perfusion scintigraphy were 71%, 76%, and 71%, respectively. The diagnostic accuracy of MR perfusion imaging was significantly higher than that of scintigraphy (p<0.001, McNemar test). There was good agreement between two observers for MR perfusion imaging (kappa statistic, 0.66) and only moderate agreement for perfusion scintigraphy (kappa statistic, 0.51). CONCLUSION: MR perfusion imaging is superior to perfusion scintigraphy in the evaluation of pulmonary parenchymal perfusion in patients with pulmonary emphysema.
Adult↗
Panacinar emphysema: CT and pathologic findings.
OBJECTIVE: To determine the ability to assess the presence and extent of panacinar emphysema with CT, two chest radiologists independently reviewed CT of 10 patients with pathologically proven panacinar emphysema and five normal controls. MATERIALS AND METHODS: Six of 15 cases had conventional 10 mm collimation CT, eight cases had conventional CT and high-resolution CT (HRCT), and one case had HRCT only. In each of the 15 cases a single CT image was compared with the inflated pathologic specimen cut in the transverse plane at the same level as the CT scan. Comparison was made between visual assessment of the severity of panacinar emphysema on CT and pathologic assessment of severity using the modified Thurlbeck panel score. RESULTS: The correlation between the assessment of extent of panacinar emphysema on CT and the pathologic grade was r = 0.90, p < 0.01 for conventional CT and r = 0.96, p < 0.01 for HRCT. There was less interobserver variation in the grading of emphysema on HRCT (mean 0.6, SD 3.9) than with conventional CT (mean 3.9, SD 11.0). Conventional CT correctly identified or excluded panacinar emphysema in 10 of 14 cases, whereas HRCT was correct in 6 of 9 cases. CONCLUSION: We conclude that HRCT allows improved correlation with the pathologic score and decreased interobserver variation than conventional CT in panacinar emphysema. However, emphysema may be missed on both techniques.
Adult↗