The immunochemistry of peptidoglycan. Antibodies against a synthetic immunogen cross-reacting with an interpeptide bridge of peptidoglycan

An albumin-peptide conjugate was synthesized, which carries pentaglycine peptides with C-terminal glycine residues as found in the interpeptide bridges of the peptidoglycan of many staphylococci. Immunization of rabbits with this synthetic immunogen yielded antisera containing predominantly antibodies against the peptide moiety of the conjugate. The quantitative precipitin and the Ouchterlony agar gel reaction with several synthetic protein-peptide-conjugates, immunoaffinity chromatography of the antisera on Sepharose-(Gly-Gly-Gly-Gly-Gly)n and hapten inhibition studies with several synthetic peptides and peptide derivatives demonstrated that the antibodies were highly specific for oligoglycine peptides with C-terminal glycine. These antibodies also reacted strongly with staphylococcal peptidoglycans with an interpeptide bridge composed of pentaglycine peptides or of pentaglycine peptides in which part of the glycine residues were replaced by L-serine. In contrast, all the peptidoglycans lacking interpeptide bridges composed of glycine residues gave no precipitin reaction at all. The final proof for identical determinant groups of albumin-(CH2CO-Gly-Gly-Gly-Gly-Gly)31 and the staphylococcal peptidoglycans applied in the precipitin reaction was furnished by double gel diffusion studies and by hapten inhibition of the precipitin reaction between antisera to albumin-(CH2CO-Gly-Gly-Gly-Gly-Gly)31 and the corresponding peptidoglycans. For rapid screening of the different peptidoglycans, a latex agglutination test was elaborated. Purified antibodies were adsorbed to latex particles, and the titers with the particular peptidoglycans were then determined. The test was highly sensitive, in that 10 nanograms of peptidoglycan could still be detected.     

Adsorption von phenolen aus den wäßrigen lösungen an nichtionogenen adsorberharzen

The adsorption and desorption of phenol and p-nitrophenol from aqueous solution on macroporous non-ionic adsorption resins and on active carbon, respectively, has been studied. The reversibility of adsorption on the resins has been observed, in opposition to the nonreversible process found on the active carbon. The adsorption isotherme data measured have been used to the surface area estimation; the method of inflection point and BET-equation have been compared. The practical identity of both methods above has been demonstrated, in the case of straight isotherme curves the BET-equation proved to be useful.     

Macro forest transducers

Xml documents conceptually are not trees, but forests. Therefore, we extend the concept of macro tree transducers (mtt's) to a transformation formalism of forests, macro forest transducers (mft's). We show that mft's form a strict superset of mtt's operating on forests (represented as binary trees). On the other hand, the transformation of every mft can be simulated by the composition of two mtt's. Although macro forest transducers are more powerful, the complexity of inverse type inference, i.e., computing the pre-image of a recognizable language, is almost the same as for tree transducers.     

Comparison of columnar water-vapor measurements from solar transmittance methods

In the fall of 1997 the Atmospheric Radiation Measurement program conducted a study of water-vapor-abundance-measurement at its southern Great Plains site. The large number of instruments included four solar radiometers to measure the columnar water vapor (CWV) by measuring solar transmittance in the 0.94-mum water-vapor absorption band. At first, no attempt was made to standardize our procedures to the same radiative transfer model and its underlying water-vapor spectroscopy. In the second round of comparison we used the same line-by-line code (which includes recently corrected H(2)O spectroscopy) to retrieve CWV from all four solar radiometers, thus decreasing the mean CWV by 8-13%. The remaining spread of 8% is an indication of the other-than-model uncertainties involved in the retrieval.     

A feature-based classification of formal verification techniques for software models

Software and Systems Modeling - Software models are the core development artifact in model-based engineering (MBE). The MBE paradigm promotes the use of software models to describe structure and...     

Enforcing termination of interprocedural analysis

Interprocedural analysis by means of partial tabulation of summary functions may not terminate when the same procedure is analyzed for infinitely many abstract calling contexts or when the abstract domain has infinite strictly ascending chains. As a remedy, we present a novel local solver for general abstract equation systems, be they monotonic or not, and prove that this solver fails to terminate only when infinitely many variables are encountered. We clarify in which sense the computed results are sound. Moreover, we show that interprocedural analysis performed by this novel local solver, is guaranteed to terminate for all non-recursive programs—irrespective of whether the complete lattice is infinite or has infinite strictly ascending or descending chains.     

Antitumorigenic effect of a mammalian lignan precursor from flaxseed

Secoisolariciresinol diglycoside (SD), a mammalian lignan precursor found in high-fiber foods, was isolated from flaxseed and tested for effects on mammary tumorigenesis in rats fed a high-fat (20%) diet. Ingestion of purified SD at 1.5 mg/day for 20 weeks starting 1 week after treatment with the carcinogen dimethylbenzanthracene resulted in a 37% reduction (p < 0.05) in the number of tumors per tumor-bearing rat and a 46% reduction (p < 0.05) in the number of tumors per tumor-bearing rat and a 46% reduction (p < 0.05) in the number of tumors per number of rats in each group. Urinary mammalian lignan excretion significantly increased (p < 0.0001) with SD treatment, indicating the conversion of SD to mammalian lignans. No enlargement or gross abnormalities of the major organs were observed in the SD-treated rats. This study showed, for the first time, that SD has an antitumor effect when provided at the early promotion stage of tumorigenesis and may contribute to the health benefits of high-fiber foods.