Bispecific multivalent antibody studied by real-time interaction analysis for the development of an antigen-inhibition enzyme-linked immunosorbent assay.

A bispecific antibody with specificities for both 7-hydroxycoumarin (7-OHC) and alkaline phosphatase (AP) was produced by chemically cross-linking two parental polyclonal antibodies. Real-time interaction analysis of the bispecific multivalent antibody (bsMAb) was performed using BIAcore, a surface plasmon resonance (SPR)-based biosensor, in order to confirm its bispecific nature. A 7-OHC-BSA conjugate was covalently immobilized to a dextran matrix to serve as the reaction surface and unconjugated bovine serum albumin (BSA) was immobilized on to a separate dextran matrix as a control surface. Immunoaffinity-purified bsMAb, parental anti-7-OHC antibody and AP were injected over both surfaces. The bsMAb was shown to bind both antigens, 7-OHC and AP, simultaneously. Comparison of the ratio of mass bound for bsMAb and AP (5:1) with the ratio of the molecular masses of bsMAb (approximately 300 kDa) and AP (85 kDa) (3.5:1) suggests that most of the bsMAb species possess both specificities. The bsMAb was employed in a one-step antigen-inhibition ELISA for the detection of 7-OHC. The assay was compared with a conventional ELISA approach employing an AP-labelled secondary antibody. The bispecific antibody approach proved to be faster and more sensitive, with a detection limit of 6 ng ml-1 as compared with approximately 50 ng ml-1 for the conventional approach. The assay was used for the quantification of free and total 7-OHC in urine samples from two healthy volunteers who had been administered coumarin. The accuracy and precision of the assay were assessed. The bispecific antibody-based assay gave similar results, accuracy and precision, but proved to be far more sensitive (limit of determination 6 ng ml-1 for total 7-OHC). It is concluded that real-time interaction analysis using BIAcor provides a rapid method for the evaluation of the bsMAb and it was verified that the bispecific product formed by chemical cross-linking of two parental antibodies offers a simple alternative for the development of a highly sensitive ELISA.

Microscopic observations on the interaction of the mycoparasite Verticillium biguttatum with Rhizoctonia solani and other soil-borne fungi.

The mycoparasitic interactions of Verticillium biguttatum with Rhizoctonia solani and with a variety of other soil-borne fungi were investigated in dual cultures. V. biguttatum interacted with various soil fungi by appressed growth along the host hyphae and infrequent penetrations. Intracellular growth and subsequent sporulation, however, only occurred with R. solani, a few binucleate Rhizoctonia and Ceratobasidium spp., and Sclerotinia sclerotiorum. Effective mycoparasitism on sclerotia was restricted to those belonging to R. solani. Electron-microscopic observations revealed that V. biguttatum can penetrate the host cell with infection tubes. This process is probably mediated by enzymatic hydrolysis of the cell wall. Subsequently, trophic hyphae develop within the host cytoplasm, ultimately resulting in death of the host cell.

[Blunt upper abdominal trauma as a complication of cardiac resuscitation]. / Das stumpfe Oberbauchtrauma als Komplikation nach kardialer Reanimation.

The case of a combined manifold rupture of the liver and spleen give rise to the discussion of the blunt abdominal trauma after extern cardiopulmonary resuscitation. A survey concerning the recent status of the diagnostic possibilities will be given according to the literature and our own experiences. The values of the different diagnostic procedures, advantages and disadvantages will be discussed.

[Cecal pole tuberculosis--an often forgotten differential diagnosis? Observations before and following tuberculostatic therapy]. / Zökalpoltuberkulose--eine oft vergessene Differentialdiagnose? Beobachtungen vor und nach tuberkulostatischer Therapie.

If the barium enema reveals stenosing changes of the terminal ileum and caecum, tuberculosis must be considered in differential diagnosis, even if pulmonary evidence of the illness is lacking. Since, however, radiographically no exclusive typical changes for the tuberculosis of the terminal ileum and caecum can be seen, the diagnosis must be checked histologically and bacteriologically. Under drug therapy an obvious decrease of the inflammation of the mucosa of the colon could be seen.

[Differential diagnosis of changes in density and structure of the foot bones]. / Differentialdiagnose der Dichte- und Strukturveränderungen des Fussskelets.

Skeletal disorders of the foot can be assessed radiologically by changes in bone density, structure and/or form. The knowledge of specific morphological criteria is a precondition for differential diagnosis. Our classification of skeletal disorders of the foot is based on the specific signs that can be observed in systemic and local diseases affecting the pedal bones.

[Calcifications in a scar keloid]. / Verkalkungen in Narbenkeloid.

Ossification as a dystrophic alteration of scar tissue is not an unusual radiologic finding in patients who have had a laparotomy. Calcification or ossification in other than abdominal scars following injury, however, represent an extremely rare entity. A case of calcifications in posttraumatic keloid forming in the submandibular soft tissue is presented and the pathogenesis is discussed.

Human skeletal muscle enolase and factors influencing its activity.

Enolase activity was determined in human skeletal muscle extracts using two procedures to measure the phosphoenolpyruvate formed. The results closely agreed, as did double determinations on bipartite muscle pieces. Activities in m. vastus lateralis quadricipitis did not differ significantly in adult males, females and 11- to 14-year-old girls. M. vastus medialis and deltoideus exhibited significantly higher activities than vastus lateralis. Endurance-trained athletes had lower enolase activities when compared to untrained subjects. The effects of changes in temperature, pH and K+ concentration in the medium were investigated and the possible physiological implications discussed.