Pulmonary arteriovenous malformations: techniques and long-term outcome of embolotherapy

Over a 10-year period, 276 pulmonary arteriovenous malformations (PAVMs) were occluded with balloon embolotherapy in 76 patients, 67 (88%) of whom had hereditary hemorrhagic telangiectasia. Eleven patients (14%) were discovered by means of family screening with measurement of arterial blood gases and chest radiography. Epistaxis, dyspnea, hemoptysis, and hemothorax occurred in 79%, 71%, 13%, and 9% of patients, respectively. Clinical histories of strokes and transient ischemic attacks were present in 18% and 37% of patients, respectively. Computed tomographic scans of 59 patients showed stroke in 36%. Sixty-five percent of PAVMs were located in the lower lobes, which correlated with the finding of more pronounced hypoxemia in the upright position. After embolotherapy, symptomatic hypoxemia was corrected, and serial values have remained constant for 5 years. Complications were minimal, and no patient required surgery. Balloon embolotherapy is effective long-term therapy for PAVMs, and family screening should be pursued because of the possibility of a higher frequency of paradoxical embolization (stroke) than previously recognized.     

Solid phase red cell adherence immunoassay for anti-HIV 1: a simple, rapid, and accurate method for donor screening

In technically developed countries in which acquired immunodeficiency syndrome is a risk to the recipients of blood or tissue, it is mandatory to screen the donor for evidence of HIV (human immunodeficiency virus) infection. Current tests, based on enzyme-linked immunoassay, are time-consuming and expensive and as such are unsuitable for developing countries. We describe a second generation test using anti-human IgG coupled to red cells as the indicator of antibody having reacted with test antigen (1). The test is complete within ten minutes, simple to perform and to read and has 100% sensitivity and 99% specificity compared with Western blot. It is ideal for the rapid screening of organ donors and for the screening of blood donors where cost is a major consideration.     

Similarities and dissimilarities between the binding ability of C1q and collagen.

Based on chemical-structural similarities between C1q and collagen, we studied their activities in reactions which are typically induced in collagen or mediated by C1q. Human C1q suppressed the collagen-induced platelet aggregation in human platelet-rich plasmas. Both human C1q and a suspension in insoluble bovine collagen inhibited in time-dependent fashion the lysis of sensitized sheep erythrocytes (EA) by guinea-pig complement. They both agglutinated sheep erythrocytes (EA and EAC4) sensitized with rabbit haemolysin, mainly in the IgM type, polystyrene latex particles complexed with heat-denatured human IgG, a combination of horse, goat and sheep globulins, or deoxyribonucleoprotein. Heating of C1q and collagen (56 degrees C, 30 min), which disrupts the collagen fold into a random coil structure, almost completely abrogated all activities of C1q and considerably reduced those of collagen, suggesting that an intact triple helix is essential for their activities. In spite of their far-ranging similarities, C1q was more potent by weight in most reactions, showed evidence of a faster rate of binding to EA, and was more sensitive to heat treatment at 56 degrees C than was collagen. on the basis of the binding activities of collagen, a model is proposed according to which platelets, sensitized erythrocytes, aggregated gammaglobulins, immune complexes and deoxyribonucleoprotein might accumulate at the site of endothelial damage where blood and its components are exposed to collagenous substances. C1q is able to inhibit all these reactions, indicating that not only is C1q collagen-like in its behaviour, but that collagen also had C1q-like properties.     

Ovarian metastases: computed tomographic appearances

Computed tomographic scans of 34 patients with ovarian metastases were reviewed to assess the radiographic appearances and to correlate these with the primary neoplasms. Primary neoplasms were located in the colon (20 patients), breast (six), stomach (five), small bowel (one), bladder (one), and Wilms tumor of the kidney (one). The radiographic appearance of the metastatic lesions could be described as predominantly cystic (14 lesions), mixed (12 lesions), or solid (seven lesions). There was one false-negative examination which showed no ovarian enlargement, although neoplastic deposits were found on the ovary at laparotomy. The cystic and mixed lesions tended to be larger in overall diameter than the solid. The metastases from gastric carcinoma appeared solid in four of five cases. The metastases from the other neoplasms had variable appearances simulating primary ovarian carcinoma.     

Activation of human platelets by antibodies to thymocytes and beta 2-microglobulin. II. Effect of purified beta 2m on the platelet aggregating and lymphocytotoxic activities of HATG and SA beta 2mG

Platelet aggregating (PAA) and lymphocytotoxic activities (LTA) of antibody preparations known to have immunosuppressive properties were studied in this work. In comparison to sheep anti-human beta-2-microglobulin globulin (SA beta 2mG), horse anti-human thymocyte globulin (HATG) was about twice as potent by weight in LTA than in PAA, suggesting that a considerable portion of antibodies in HATG had been generated against lymphocyte specific antigens. Evidence is presented that not only the LTA but also the PAA is a direct effect of both HATG and SA beta 2mG on lymphocytes and platelets. The specificity of the antibodies was investigated by means of purified human urinary beta-2-microglobulin (beta 2m). Beta-2-microglobulin had no detectable inhibitory effect on the LTA and, in most cases, on the PAA of HATG. Even in a highly sensitive assay system, no more than 5 to 7% of the total PAA of HATG was inhibitable by beta 2m. In contrast, both the PAA and LTA of SA beta 2mG could be inhibited by beta 2m in a time- and dose-dependent fashion. The results prove that HATG and SA beta 2mG exert their actions through different membrane components on both platelets and lymphocytes. This is consistent with our earlier observation that the PAA of HATG and SA beta 2mG may widely dissociate among various human platelet-rich plasmas. Relatively low response to anti-beta 2m in the presence of high reactivity to ALG/ATG can also be explained by varying plasma levels of beta 2m. Finally, inhibition of the PAA of SA beta 2mG by purified beta 2m provides the first model where the platelet aggregating effect on an inducer (anti-beta 2m) can quantitatively be blocked by its specific "solubilized" receptor (beta 2m) whose structure is fully understood.