Pulmonary hamartoma: CT findings

Forty-seven patients with a proved (n = 31) or presumed (n = 16) diagnosis of pulmonary hamartoma were studied prospectively by thin-section computed tomography (CT). CT criteria for hamartoma included a diameter of 2.5 cm or less, a smooth edge, and focal collections of fat or fat alternating with areas of calcification. No case of cancer (n = 283) or metastatic disease (n = 72) fulfilled these criteria. Seventeen hamartomas with no detectable calcium or fat were not diagnosed by means of CT. Two other lesions contained diffuse calcium deposits. In 28 lesions, a CT diagnosis of hamartoma was based on the detection of fat (n = 18) or calcium plus fat (n = 10). Twelve such cases were proved histologically by means of thoracotomy or needle biopsy; the remainder, including eight in asymptomatic patients aged 65 years or older, were managed with conservative follow-up.     

Fracture nonunion: CT assessment with multiplanar reconstruction

Nineteen patients with suspected or possible fracture nonunion underwent computed tomography (CT) with multiplanar reconstruction (MPR). Each case represented a difficult problem in fracture management in which clinical and conventional radiographic examinations had failed to provide a definitive diagnosis. CT with MPR demonstrated nonunion in 13 of 19 cases by delineating the lack of bone bridging across the fracture site in multiple planes. Variable amounts bridging were detected in six cases, indicating partial healing or delayed union. Evaluation of fracture healing with MPR was possible despite remaining metal hardware (ten cases), multiple operations (15 cases), or bone grafting (five cases). CT with MPR aided surgical planning and affected treatment options by providing a more detailed assessment of malalignment and angular deformities, the magnitude of the gap in bone, and the integrity of the adjacent weight-bearing joints in multiple projections. It is an important new modality for evaluating fracture nonunion.     

Hyaline cartilage-origin bone and soft-tissue neoplasms: MR appearance and histologic correlation

Magnetic resonance (MR) images and histologic studies of 16 chondroid-matrix lesions were reviewed to determine if any distinctive morphologic or signal features might be discerned. Ten biopsy-proved nonchondroid bone lesions were compared in terms of configuration and signal characteristics. The tumor matrix had a distinctive appearance of homogeneous high signal intensity in a defined lobular configuration on images of all hyaline cartilage lesions obtained with a long repetition time and a long echo time. The areas of hyperintensity relative to muscle corresponded to areas of hyaline cartilage matrix with its uniform composition, low cellularity, and high water content; the lobular morphologic characteristic had an identical histologic correlate. The chondroblastomas, clear-cell chondrosarcoma, and synovial chondromatosis demonstrated a much more cellular stroma, with only scattered islands of chondroid matrix, and were isointense or hypointense compared with muscle on all MR sequences. The distinctive lobular, high-intensity MR appearance was not seen in the ten nonchondroid bone lesions.     

Avascular necrosis versus other diseases of the hip: sensitivity of MR imaging

Magnetic resonance (MR) imaging of the hip has been useful in the examination of patients for the presence of avascular necrosis (AVN). In the detection of AVN, MR imaging is more sensitive than computed tomography or nuclear scintigraphy. This study assessed the usefulness of MR imaging in the differentiation of AVN from other hip diseases. Twenty-two cases of non-AVN hip disease were matched with 23 biopsy-proved cases of AVN and ten normal controls. MR images were rated in a blinded manner by five experienced radiologists, and receiver operating characteristic (ROC) analysis was performed on the data. In the discrimination of AVN from other hip diseases or from normality, the A(z) value (the area under the ROC curve) was 98.6. With a specificity of 98%, MR imaging was 97% sensitive in the differentiation of AVN from normality, 85% sensitive in the differentiation of AVN from non-AVN disease, and 91% sensitive in the differentiation of AVN from both conditions. MR imaging may therefore help discriminate between AVN and other hip diseases.     

Angiography in the diagnosis and staging of pelvic neoplasms

The efficacy of arteriography in the staging of pelvic neoplasms was examined in 447 patients. It was found to be most useful in defining advanced neoplastic disease, improving accuracy of staging in these patients by about 18%. In patients with early pelvic neoplastic disease, arteriography reduced the number of false positives.     

Fertility regulating agents from plants.

The WHO Special Programme of Research, Development and Research Training in Human Reproduction has established a 6-center program to investigate new fertility regulating agents from plants for use in humans. Establishment of the project was preceded by a comprehensive search of the literature, including the following sources: 1) articles on medical botany; 2) reports of testing crude plant extracts for fertility regulating purposes; 3) reports of in vitro effects of plant extracts; and 4) reports of a limited number of experimental studies in human subjects. The limitations of these sources of data are discussed. Information on 3000 plants was collected and computerized, using a weighting system, in order to assign priorities on the plant substances most promising for further study. The 6 centers will then procede to initiate pharmacological and chemical studies on the priority substances. Both male and female antifertility agents are included in the study.     

Multiple percutaneous access routes to multiple calculi, calculi in caliceal diverticula, and staghorn calculi

For expeditious removal of multiple calculi from certain locations in the pyelocaliceal system, the use of multiple percutaneous entry routes is advocated. The accessibility of different regions of the pyelocaliceal system from different percutaneous entry sites was mapped out after experience with the percutaneous removal of 87 solitary and 37 multiple renal calculi. A technique allowing limited access to calculi in caliceal diverticula and hydrocalices distal to stenotic infundibula was used, along with a technique for percutaneous infundibuloplasty, which is necessary to ensure drainage of such obstructed calices or caliceal diverticula after percutaneous lithotripsy. In 34 of 37 patients with multiple or staghorn calculi, all calculi were eventually removed by these methods. The use of multiple entry routes did not increase the risk of reduced renal function. Moreover, improved drainage through the resultant multiple nephrostomy tubes and transinfundibular stents has reduced the incidence of postoperative septicemia.     

Gene expression of plasminogen activation cascade components in human term gestational tissues with labour onset

The plasminogen activation cascade is thought to play a critical role in labour-associated remodelling events, such as fetal membrane rupture and placental separation. The aim of this study was to quantify, by Northern analysis, the gene expression of urokinase plasminogen activator (UPA), urokinase receptor (UPAR) and plasminogen activator inhibitor type-2 (PAI-2) in human gestational tissues. Amnion, choriodecidua and placenta were collected from women before, during and after spontaneous-onset labour at term. The expression of UPAR mRNA was significantly (P < 0.05) increased in amnion tissue during and after labour and delivery, compared with the before-labour group. In contrast, UPAR gene expression in choriodecidua and placenta was not significantly altered in association with labour onset. PAI-2 mRNA expression was also significantly (P < 0.05) increased in amnion after labour. No statistically significant differences were observed in choriodecidua or placenta PAI-2 mRNA with labour onset. Neither was any significant effect of labour status on UPA mRNA identified in any of the tissues examined. This study is the first to describe a significant increase in UPAR and PAI-2 gene expression in human amnion tissue with labour. These data are consistent with the hypothesis that, during labour, up-regulation of UPAR expression in amnion serves to localize active UPA at the cell surface, thereby increasing proteolytic activity in fetal membranes. Increased PAI-2 in amnion after labour may provide a regulatory 'switch' to cease further proteolysis in this tissue type. In conclusion, the data obtained support the proposal that the plasminogen activation cascade contributes to the rupture of fetal membranes during active labour.