Biophysical study of bioactive-substance conformation and interaction with drugs in solution

The interaction of salicylic acid (S.A), salicylamide (S.M) with nucleic acid base derivatives such as 9-ethyl adenine (A), 1-cyclohexyl uracil (U), 2′, 3′-benzylidine-5′ trityl-cytidine (C), guanosine-2′, 3′, 5′-isobutylate (G) has been spectroscopically investigated to determine the binding mechanism. NMR, and IR spectra were measured in nonpolar solvents. The association constant K of the formation of complex was calculated from the IR spectra. Compounds S.A and a form a 1∶1 or 1∶2 cyclic hydrogen-bonded complex depending on the sample concentration. Compounds S.A and U form a 1∶1 or 1∶2 hydrogen-bonded complex on the sample concentration. Compounds S.A and C form a 2∶1 hydrogen-bonded complex at low concentration (0.0016M). Compound S.A binds compound G, but its binding does not completely break the self-association of compound G. Compound S.M binds compounds A,U,C,G very weakly.     

Necrotizing sialometaplasia masquerading as residual cancer of the lip

Necrotizing sialometaplasia is a benign disorder that histologically can mimic carcinoma. It is thought to develop as a result of ischemia or adjacent tissue injury. A patient is described who underwent a Mohs' micrographical fresh-tissue excision of one-third of the upper lip for basal cell carcinoma. By the time she was ready for reconstruction, a marked eczematous reaction developed to a polymyxin neomycin preparation (Neosporin ointment) at the wound edges. Reexcision of the wound margins before a flap reconstruction revealed necrotizing sialometaplasia on histopathological examination. This incidental finding fortunately was not mistaken for residual tumor. To prevent over-diagnosis and over-treatment of presumed malignancies, an awareness of necrotizing sialometaplasia is essential for all surgeons operating on mucosal surfaces in the head and neck.     

The value of magnetic resonance imaging at 1.5 T in the evaluation of the scrotal content

50 patients with a broad variety of scrotal disorders were evaluated in form of a prospective study by high-resolution scrotal sonography and magnetic resonance imaging at 1.5 T with high-resolution surface coils. Basic anatomic correlations to normal structures of the scrotum were studied in 4 fresh cadaver testicles without pathology. Magnetic resonance imaging is sensitive and specific, but time-consuming and expensive.     

Phenotypic and functional characterization of a panel of cytotoxic murine NK cell clones that are heterogeneous in their enhancement of Ig secretion in vitro

NK cells not only function as cytotoxic effector cells, but also have immunoregulatory roles including the enhancement of Ig secretion. To have a stable and uniform population of NK cells to study their role in Ig secretion, we generated murine NK clones. Thus, culture of splenocytes from mice that were homozygous for a mutation in the p53 tumor suppressor gene (p53-KO) with IL-2 and poly(IC) resulted in a long-term NK line, from which four stable clones were derived. This approach also yielded a long-term NK line from splenocytes of normal C57BL/6 mice. Identification of the clones as members of the NK lineage was based on large granular morphology, expression of NK-TR and absence of TCR gene rearrangement. Flow cytometry revealed that all clones expressed IL-2R alpha and beta, chains and B220, but no CD3, NK1.1, DX5 or Ly-49. RT-PCR analysis showed heterogeneity in NK1.1 gene expression, and demonstrated expression of perforin and several granzymes in all clones. Three out of four clones lysed YAC-1, but not P815 target cells, corresponding to a pattern of NK specificity. All NK clones enhanced Ig secretion in an in vitro model for T cell- independent type 2 antigens, albeit to varying degrees. We found no correlation between the degree of helper activity of the NK clones and the level of their cytotoxic activity on YAC-1 targets. Thus, we established murine NK clones, and show that they mediate both cytotoxicity and enhancement of Ig secretion.      

Indications and results of Politano-Leadbetter antireflux-plasty in 565 cases of ureterorenal surgery

The Politano-Leadbetter antireflux procedure is a standardized and safe method for the treatment of primary and secondary reflux persisting after successful therapy of infravesical obstruction. Indications for antireflux surgery depend on reflux classification, age, urethral calibration and evaluation of position and shape of the ureteral orifice, associated malformations and successful antimicrobial therapy. Reflux was cured in 90.4 per cent of 565 ureterorenal units in 361 children and 103 adults. A persisting reflux occurred in 5.1 per cent and a stenosis of the terminal ureter requiring reimplantation occurred in 0.7 per cent. The overall rate of reinterventions was 8.1 per cent. This low complication rate makes surgical correction advisable if urinary tract infection and primary reflux cannot be eradicated by continuous antimicrobial therapy.     

Genetically modified and wild soybeans: an immunologic comparison.

Most traits introduced into genetically engineered crops result from the expression of new proteins. As the first step toward assessing the allergenic potential of genetically modified organism (GMO) food, immunologic and physicochemical characterizations are needed. We prepared crude extract from GMO soybeans, wild soybeans, curd, and soy milk and then performed sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). After acidification with HCl, the samples were separated to globulin and whey. To evaluate changes in protein composition, either the samples were heated or pepsin was added. Polymerase chain reaction with primer encoding the 35S-promotor and the 3-enol-pyruvyl-shikimat-5-phosphat-synthase gene were performed, respectively, to detect the GMO component. SDS-PAGE results showed definite protein bands at 80 kDa in GMO soybean, 50 kDa in wild soybean, and a similar distribution of protein bands was noticed below 40 kDa. It was difficult to observe protein distribution because of modifications that occurred during processing in soybean-processed products. After heating, proteins of GMO and wild soybeans showed similar distributions and no distinct bands were detected at 50 and 80 kDa. Although SDS-PAGE analyses of raw GMO and wild soybeans differed, the same protein bands of 68, 37, and 20 kDa were observed in the globulin fraction after acidification. After adding pepsin, 20- and 68-kDa bands were found preserved in GMO and wild soybeans. The polymerase chain reaction procedures with primers specific to GMO soybeans showed that GMO soybeans and some curd samples included a GMO component. The skin test results of 49 patients showed 13 positive results to wild soybeans and 8 positive results to GMO soybeans. One patient had a positive skin test result to GMO soybeans only. Sera from nine patients with positive skin tests to the crude extract and a positive capsulated allergen product test to the soybean antigen were used for the immunoblotting of GMO and wild soybeans. GMO soybeans revealed a unique strong immunoglobulin E binding band at 25 kDa in some patients and wild soybeans showed a strong immunoglobulin E binding band at 30-36 kDa. To assess the allergenicity of GMO food, more research, including a selection of controlled sample materials and immunoassays of qualified sera, is needed.