从远志中分离鉴定出一种多巴胺受体活性化合物

从中药远志中提出一种多巴胺受体的配基,四氢非州防己胺。此化合物在体外可抑制[³H]SCH23390和[³H]螺哌隆与大鼠纹状体膜的结合,IC₅₀值分别为0.75±0.08μmol·L^-1和0.92±0.10μmol·L^-1。它在体外还能抑制[³H]哌唑嗪和大鼠脑皮质细胞膜结合(IC₅₀值为46μmol·L^-1),但不能改变[³H]QNB及[³H]muscimol对膜的结合。Scatchandplot分析显示此化合物对[³H]SCH23390和[³H]螺哌隆与膜结合的抑制作用是通过竞争性与非竞争性混合机制而实现的。     

Hyperparathyroidism: comparison of MR imaging with radionuclide scanning

Twenty-three patients with hyperparathyroidism were evaluated preoperatively with magnetic resonance (MR) imaging. Twenty patients also underwent thallium-201/technetium-99m scintigraphy. Of 22 patients with primary hyperparathyroidism, 12 had persistent or recurrent disease. One had secondary hyperparathyroidism due to end-stage renal disease. MR imaging allowed accurate localization of abnormal parathyroid glands in 64% evaluated prospectively and 82% evaluated retrospectively. Scintigraphy allowed localization of 60% evaluated prospectively and 70% retrospectively. The two imaging modalities together allowed detection of 68% evaluated prospectively and 91% retrospectively. MR imaging allowed detection of two of five mediastinal adenomas evaluated prospectively and four of five retrospectively. In patients who underwent both imaging studies, MR was more successful in those with previous neck surgery (73% evaluated prospectively and 91% retrospectively) than in those with no prior surgery (57% prospectively and 71% retrospectively). Scintigraphy allowed accurate localization in 64% evaluated prospectively and 64% retrospectively in patients with previous surgery versus 57% prospectively and 86% retrospectively in patients with no prior neck surgery. Four false-positive results were obtained with MR imaging and three with scintigraphy. MR imaging was useful for parathyroid localization in patients with hyperparathyroidism, particularly in patients requiring additional surgery.     

Urinary bladder MR imaging. Part II. Neoplasm

The potential of magnetic resonance (MR) imaging for the evaluation and staging of bladder tumors was analyzed in 15 patients (11 cases of transitional cell carcinoma, two adenocarcinomas, one leiomyosarcoma, and one leiomyoma). Neoplasms were characterized by size, site, and growth pattern, and the accuracy of the staging was compared with the results of computed tomography and pathologic study. Malignancies were accurately detected and staged by MR imaging in 12 of 14 patients (85%). Tumor site and degree of bladder distention did not adversely affect detection; tumors greater than 1.5 cm were detected easily. In situ carcinoma (stage Tis) was not detected on MR images. Imaging in both sagittal and transverse planes was needed for optimal bladder evaluation. Bladder carcinoma was best displayed with a short echo delay time (TE) of 28 msec and repetition (TR) times of 1.0-2.0 sec: TR = 1.0 gave 34% contrast and TR = 2.0 gave 36% contrast between tumor and surrounding urine. Bladder-wall invasion by tumor was best evaluated with long TR (2.0 sec) and long TE (56 msec) (82% contrast). For assessing tumor extension into perivesical fat, short TR (0.5 sec) and TE (28 msec) were optimal (58% contrast). MR imaging offers an increased sensitivity for tumor detection and promises to greatly improve the staging of bladder neoplasms.     

Epipericardial fat pad: CT findings

Epicardial and mediastinal fat around the apex of the heart may produce the classic appearance of a cardiac fat pad filling in the anterior cardiophrenic angle on a lateral chest radiograph. A review of 50 computed tomographic (CT) scans of the chest that were normal save for possible cardiomegaly, together with chest radiographs obtained within a 14-day interval, revealed a wide variation in the configuration of this fat pad in 16 patients (32%). Depending on geometric circumstances, the fat pad may produce a well-marginated region of increased density, a region of increased density with poor margination, or an area of reduced density lying anterior to the heart. In an additional four patients (8%), however, a simulation of a cardiac fat pad was produced by cardiomegaly alone or by relative levoposition of the heart. In these four patients, the left side of the heart contacted the chest wall on the left over a larger than normal area and thereby excluded lung from the vicinity, simulating the appearance of a fat pad where none existed.     

Hepatic and splenic injury in children: role of CT in the decision for laparotomy

Clinical and radiographic records of 274 children who were examined with abdominal computed tomography (CT) after blunt abdominal trauma were retrospectively evaluated to test the hypothesis that CT can assist in decisions to perform laparotomy in children with hepatic or splenic injury. CT demonstrated parenchymal injuries in 36 patients (13%) or 20 livers and 21 spleens. Injury to these organs was categorized as minor (39%), moderate (39%), and severe (21%) according to an assessment of the percentage of parenchymal involvement. Hemoperitoneum was detected in 27 of 36 patients (75%). One of 13 (4.7%) with a moderate to large splenic injury underwent splenorrhaphy because of persistent bleeding. One of 12 (5%) with a moderate to large hepatic injury required late operative intervention due to a large necrotic segment. Both children had a large amount of peritoneal fluid. Two of 16 patients (13%) with moderate to large hemoperitoneum required surgery for liver or splenic injury. The decision for laparotomy should not be based on the extent of injury as shown at CT but on the physiologic condition of the child.     

Cancellation of preoperative breast localization procedures: analysis of 53 cases

Among 603 patients scheduled for a breast biopsy at the authors' institution in 1987, the biopsy was canceled on the day of the procedure in 53 (8.8%). All had been referred from other facilities. An analysis of the original mammograms and the additional imaging procedures performed is presented. The reasons for termination of the planned biopsies include (a) no mass present (n = 22), (b) aspiration of a mass (n = 13), (c) skin calcifications (n = 9), (d) random calcifications (n = 4), (e) skin artifacts (n = 3), and (f) other (n = 2). Practicing radiologists should adapt rigid criteria for biopsy recommendation and propose radiographic follow-up for low-suspicion abnormalities detected.     

Cholecystitis: detection with MR imaging

The role of magnetic resonance (MR) imaging in the detection of gallbladder disease was evaluated in 39 individuals (16 healthy, five with asymptomatic gallstones, and 18 with clinical symptoms of gallbladder disease). MR imaging was performed after they fasted for 12 hours. Imaging sequences included a combination of repetition times (TR) of 0.5 and 1.5 sec and echo times (TE) of 28 and 56 msec. On the images obtained at TR = 0.5 sec and TE = 56 msec, gallbladder bile was hyperintense compared with the liver in all healthy and asymptomatic subjects and was hypointense (n = 9), isointense (n = 4), or hyperintense (n = 5) in symptomatic patients, eight of whom had surgical confirmation of cholecystitis. Comparison of normal versus pathologically proved cases for the presence of gallbladder disease yielded a specificity of 100%, sensitivity of 75%, and a significant difference of P less than .01. Thus, with a pulse sequence of TR = 0.5 sec and TE = 56 msec, MR was sensitive in detecting gallbladder disease. However, the role of MR in the radiologic workup of gallbladder disease will be determined by more experience with this modality.