The monoclonal antibody Ki-67 reacts with a human nuclear cell proliferation-associated antigen that is expressed in all active parts of the cell cycle. Recently we have raised monoclonal antibodies, MIB 1-3, against recombinant parts of the Ki-67 antigen. These antibodies are true Ki-67 equivalents, as demonstrated by immunostaining of fresh specimens, biochemistry, and molecular biological techniques. Formalin-fixed, paraffin-embedded sections routinely processed for immunohistochemistry failed to stain for Ki-67 and MIB 2. Antibodies MIB 1 and MIB 3 labelled mitotic figures, while non-mitotic proliferating cells were negative under these conditions. However, when dewaxed microwave oven-processed paraffin sections of formalin-fixed tissues were used, MIB 1 and MIB 3 gave strong nuclear staining of those cells presumed to proliferate under a variety of normal and neoplastic conditions. Moreover, routine decalcification or depigmentation techniques did not alter the immunoreactivity of MIB 1 and MIB 3 with microwave-processed paraffin sections. This method is highly reproducible, easy to perform at low cost, and no additional technical skill is needed because after microwave treatment just routine immunohistochemical methods are used. Since we have successfully applied this new method to sections obtained from paraffin blocks stored for a long time (in one case more than 60 years), the assessment of cell kinetics through the detection of Ki-67 antigen is now possible on archival material collected in histopathology departments all over the world.

The eggs of the parasitic trematode Schistosoma mansoni are powerful inducers of a T helper type 2 (Th2) immune response and immunoglobulin E (IgE) production. S. mansoni egg extract (SmEA) stimulates human basophils to rapidly release large amounts of interleukin (IL)-4, the key promoter of a Th2 response. Here we show purification and sequence of the IL-4-inducing principle of S. mansoni eggs (IPSE). Stimulation studies with human basophils using SmEA fractions and natural and recombinant IPSE as well as neutralization and immunodepletion studies using antibodies to recombinant IPSE demonstrate that IPSE is the bioactive principle in SmEA leading to activation of basophils and to expression of IL-4 and IL-13. Regarding the mechanism of action, blot analysis showed that IPSE is an IgE-binding factor, suggesting that it becomes effective via crosslinking receptor-bound IgE on basophils. Immunohistology revealed that IPSE is enriched in and secreted from the subshell area of the schistosome egg. We conclude from these data that IPSE may be an important parasitederived component for skewing the immune response toward Th2.Infection with the parasitic trematode Schistosoma mansoni leads to a pronounced Th2 1 response and to elevated IgE production both in humans and in experimental animals. The definition of parasite-derived products capable of skewing the immune response toward Th2 would not only enhance our understanding of the defense mechanisms involved in helminth infections but may also lead to new insights into the pathogenesis of immediate-type hypersensitivity diseases such as asthma. However, in contrast to our increasing understanding of how pathogen-derived products can initiate Th1-type immune responses, there is so far little detailed knowledge about the nature of the parasite-derived molecule(s) and the underlying mechanisms that trigger and/or amplify a Th2-type reaction. In S. mansoni infection, a critical role in inducing a polarized Th2 response is played by the egg stage of the parasite (1), since a Th2 response and IgE production are only observed after egg deposition or following injection of schistosome eggs (2) or extracts thereof (3) into naive animals. By contrast, the initial larval (schistosomula) and adult worm stages rather induce a response skewed to Th1.It is now firmly established, both in vivo and in vitro, that the cytokine profile present during an immune reaction is an important element in directing the response to Th1 or Th2 and that IL-4 is the key cytokine responsible for biasing the immune reaction toward a Th2 phenotype (4 -7). In the human system, basophils are a prominent source of IL-4 and IL-13; these cells secrete large amounts of IL-4 and IL-13 in response to IgE-receptor cross-linking or activation by a combination of IL-3 and C5a (8, 9). Indeed, human basophils can be viewed as "innate Th2-type" effector cells, since IL-4 and IL-13 are expressed in a very restricted manner without production of any of the cytokines involved in Th1-type immune responses. We therefore ...

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One hundred paraffin-embedded cervical biopsy specimens were tested for the presence of human papilloma virus (HPV) by in situ hybridization (ISH), and by direct and indirect in situ PCR (IS-PCR) in order to evaluate the efficiency of the different in situ methods in detecting HPV infection. ISH was performed using either commercial DNA probes or a cocktail of 5'-digoxigenin labeled oligoprimers. The same were used for ISH during indirect IS-PCR. To enhance the sensitivity of ISH several polymers, i.e., polyvinyl alcohol (PVA), polyethylene glycol, and polyvinylpyrrolidone were added to the alkaline phosphatase nitro blue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP) reaction. Furthermore, tyramide signal amplification (TSA) was tried for signal amplification. Those samples treated with PVA during the NBT/BCIP reaction did not show any signal amplification whereas those treated with TSA exhibited a dramatic increase in sensitivity with usually acceptable signal to noise ratios. Our results show that, regarding sensitivity, ISH with subsequent signal amplification by TSA can be used as an almost equivalent alternative to the more cumbersome IS-PCR on routinely processed tissue specimens. When considering reproducibility, it is superior to IS-PCR.

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