Interaction of platelet plasma membranes with thrombin-activated platelets

This study described the binding of platelet plasma membranes to either control or thrombin-activated platelets. Glycoproteins in plasma membranes isolated from human platelets were labeled by oxidation with periodate followed by reduction with [3H]NaBH4. Labeled membranes were incubated with either control or thrombin-activated platelets. The amount of membranes bound was measured by separating platelets with bound membranes from solution by rapid centrifugation through 27% sucrose and determining the amount of radioactivity associated with platelets. Five- to sevenfold more membranes bound to thrombin- activated platelets than to control platelets. This enhanced binding of labeled membranes was completely inhibited by an excess of unlabeled platelet membranes. Human erythrocyte membranes had little affinity for either washed or thrombin-activated platelets and therefore did not compete for platelet-membrane binding. Binding of platelet membranes to thrombin-treated platelets was inhibited by prior incubation of the platelets with PGI2 suggesting that the enhanced binding of membranes was to activated platelets. This study demonstrates that the purified platelet membranes have functional sites that can mediate membrane binding to platelets and that quantitation of membrane binding appears to reflect the increased aggregation capability of activated platelets.     

The major radioiodinated cuticular antigens of Onchocerca gibsoni microfilariae are neither species nor onchocerca specific

The possible role of microfilarial surface (cuticular) antigens in immuno-diagnosis of human filarial infections has been assessed using microfilariae (mf) of the cattle parasite Onchocerca gibsoni. A Triton X-100 extract of 125I-labeled O. gibsoni mf was reacted with a panel of sera from humans infected with Onchocerca volvulus, Wuchereria bancrofti and Schistosoma japonicum as well as sera from uninfected controls. Results of these immunoprecipitations indicated that sera from humans infected with O. volvulus or W bancrofti contain antibody specificities recognising certain of the radioiodinated cuticular proteins of O. gibsoni mf. Two-dimensional gel analysis and subsequent autoradiography of these immunoprecipitates showed that 8 radioiodinated proteins recognised by sera from calves injected with O. gibsoni mf were also immunoprecipitated by sera from humans infected with either O. volvulus or W. bancrofti. Thus there appear to be no major radioiodinated cuticular antigens of O. gibsoni mf which are species or onchocerca specific.     

FM sonography in diffuse liver disease: prospective assessment and blinded analysis

FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease.     

‘Must try harder?’: A family empowerment intervention for acquired brain injury

This paper describes an intervention aimed at empowering parents of child survivors of acquired brain injury (ABI) in their interaction with teachers and other professionals involved in their child's education. The particular characteristics of the late morbidity of child ABI led to the design of an intervention in the form of a video and informational booklet that is the property of the family. Early response to the intervention has been extremely positive, although formal evaluation has been unexpectedly challenging.     

Asbestos-related focal lung masses: manifestations on conventional and high-resolution CT scans

In 260 asbestos-exposed individuals evaluated by means of computed tomography (CT), 43 unsuspected pulmonary masses were found in 27 individuals. The masses included fissural pleural plaques (n = 10), dense fibrotic bands (n = 3), round atelectasis (n = 11), carcinomas (n = 3), and other presumed benign masses (n = 16). The most helpful features in the diagnosis of rounded atelectasis with CT were (a) contiguity to areas of diffuse pleural thickening, (b) a lentiform or wedge-shaped outline, (c) evidence of volume loss in the adjacent lung, and (d) a characteristic "comet tail" of vessels and bronchi sweeping into the margins of the mass. Less advanced areas of focal atelectasis had fewer classic features. Intrafissural pleural plaques were readily identified with high-resolution CT. In asbestos-related masses, the demonstration of stability over time is necessary. Careful interpretation of CT and high-resolution CT features and close surveillance can obviate the need for biopsy in the majority of instances.     

Practical and technical considerations in establishing an intraoperative radiation therapy program in the community practice

The Radiation Oncology Center in Sacramento, California, has developed a procedure for establishing an intraoperative radiation therapy facility in a community practice. The logistics pertaining to personnel, equipment, physical measurements, and quality assurance are presented. Particular emphasis is given to the most effective means of acquiring the large quantity of data needed to ensure a program of acceptable quality.