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Previous studies have shown that the small-bowel shunt operation for morbid obesity may be followed by signs of enhanced cell-mediated immunity and polymorphonuclear (PMN) granulocyte bactericidal capacity. In the present study seven patients, operated 4 months--4.5 years previously and exhibiting postoperative arthralgias, arthritis, and/or skin rashes, were investigated with regard to their PMN adherence and bactericidal capacity and plasma levels of complement factors 3 and 4 (C3 and C4). There patients showed a decreased PMN bactericidal capacity compared both with 10 other shunt-operated patients without skin and joint symptoms and with healthy controls, whereas PMN adherence was lower than for the non-symptomatic patients but similar to that of the controls. Two patients had C3 levels above the reference value; all had normal C4 values. Thus, a small-bowel shunt operation for obesity, complicated by skin and joint symptoms, might be associated with decreased PMN bactericidal capacity.

Three hybridoma clones producing IgM antibodies against actin were obtained from mice immunized with purified virions of paramyxoviruses. When tested on growing lung fibroblasts, ascites fluids of all clones stained in immunofluorescence cytoplasmic bundles of microfilaments, but also fibrillar networks. On colchicine-treated cells, perinuclear coils were seen in addition to microfilament bundles. In addition, one clone gave a pronounced speckled staining to the nuclei. Absorption of the ascites fluids with purified actin abolished all staining patterns. Using the Western blotting technique the antibodies reacted with both actin and vimentin polypeptides. DNase I abolished the staining of the actin filaments and of the nuclei, but left the vimentin pattern unimpaired. Thus, the monoclonal antibodies evidently reacted with epitopes common to actin and vimentin.

The F-actin-depolymerizing factor (ADF) of human serum was purified and identified as a 93000-daltons protein. The concentration of ADF was calculated to 120-150 micrograms/ml in four normal sera and about half as much in three sera from leukemia patients treated with cytostatic drugs. In the presence of Ca2+ ADF shortened actin filaments into fragments, the size of which was correlated to the actin: ADF molar ratio, as judged by electron microscopy. The severing of F-actin was not necessarily followed by an increase in the quantities of monomeric actin, as determined by a DNase I inhibition assay and a sedimentation assay. The findings indicated that ADF shortens filamentous actin by breaking bonds between adjacent actin molecules thereby forming stable ADF-actin complexes, without a monomeric net release. The effect of ADF on F-actin was rapid and was reversed upon chelation of Ca2+. ADF cross-reacted immunologically and exhibited similarity in reaction mechanism with gelsolin, the Ca2+-dependent F-actin-severing protein from macrophages. This implies that the proteins are both structurally and functionally related. The physiological role of ADF may be to handle actin released at cell destruction, probably by forming ADF-G-actin 1:1 complexes thereby preventing formation of actin filaments.

Seventeen human hematopoietic cell lines were tested by indirect immunofluorescence (IF) for reactivity with human serum containing smooth-muscle antibodies (SMA). The correlation of the IF pattern to the cell surface ultrastructure was revealed by scanning electron microscopy (SEM). Lymphoma cells, viewed by SEM, had short villi over the entire cell surface, but, by IF, showed a type of membrane fluorescence. Cells of lymphoblastoid lines had thin, long surface villi, sometimes asymmetric but most often distributed over the whole cell surface. Myeloma and leukemia cells, which had few membrane villi but a surface covered by "blebs" as revealed by SEM, demonstrated, by IF, only a few stub-like projections extending from the surface. Time-lapse cinematography revealed that the intensity and pattern of SMA staining were also correlated to the degree of motility. Indirect IF with human SMA-positive serum might be used in the classification of cell lines derived from human hematopoietic tissue.

The digital skin microcirculation was studied by vital capillaroscopy in 32 consecutive patients with Raynaud's phenomenon. A detailed classification (stages 0-6) of the capillary abnormalities based upon observations of the capillaries in many different sites of the fingers was used. Associated diseases were searched for by an extensive clinical and immunological investigation. Seventeen (53%) of the patients had distinct structural changes in the capillaries but only 6 of them showed a restricted total digital circulation. Fifteen (88%) of these 17 patients displayed an underlying disease and/or immunological abnormalities. The corresponding figure for patients with mild or no capillary changes was 40% (p less than 0.01). Thus, the presence of marked (greater than or equal to stage 3) skin capillary abnormalities seems to be a good indicator of an associated systemic disease. The majority of patients in this category improved their capillary status during successful treatment of the underlying disease. We conclude that the form of capillaroscopy used in this study is a sensitive method for evaluating disturbances of the skin microcirculation in patients with Raynaud's phenomenon. The method may also contribute to the clinical evaluation of patients with this syndrome by identifying those with an underlying systemic disease.