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Protein–ligand interactions are of fundamental importance in almost all processes in living organisms. The ligands comprise small molecules, drugs or biological macromolecules and their interaction strength varies over several orders of magnitude. Solution NMR spectroscopy offers a large repertoire of techniques to study such complexes. Here, we give an overview of the different NMR approaches available. The information they provide ranges from the simple information about the presence of binding or epitope mapping to the complete 3 D structure of the complex. NMR spectroscopy is particularly useful for the study of weak interactions and for the screening of binding ligands with atomic resolution.

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Primary gastrointestinal lymphoma represents approximately 1% of all gastrointestinal neoplasms. Gastric involvement is more common than small or large intestine and carries a better prognosis. Abdominal pain and weight loss may be the only manifestations and may be present for months or years before the diagnosis is made. Perforation and obstruction occur infrequently. Multiple tumors constitute 8% of cases. Although barium studies and endoscopy reveal the lesion in a high percentage of cases, exploratory celiotomy is not infrequently required for diagnosis. Only one-third of lymphomas are confined to the bowel at laparotomy. Histologically one-third are reticulum cell sarcomas and the remainder lymphosarcoma or lymphocytic lymphoma. Five year survival overall was 38%. Curative resections yielded a survival of 60% regardless of site while palliative resections offered only a 17% chance of cure. As expected, survival was inversely proportional to extent of nodal spread. Postoperative radiotherapy is recommended for residual disease.

Book reviews preparations can be made by drying the stained section in air and then mounting in Fluormount (E. Gurr, Ltd.), though this treatment sometimes causes a reduction in fluorescence. COMMENTThe freeze-dried sections are equally suitable for identifying the autoantibody against thyroglobulin (Figure 1), and the CA2 antibody first described by Balfour et al. (1961) for which immunofluorescence provides the only known method of detection. The technique is also sufficiently reliable for use in reverse, so to speak, for studying the reactions of thyroid biopsy material with autoimmune sera of known specificity.Because of the excellent preservation of stored sections, there is clearly no necessity for all laboratories interested in the detection of autoantibodies to thyroid to carry out the freeze-drying, embedding, and microtomy themselves. It should be possible to have embedded blocks or mounted sections prepared commercially for routine laboratory use.

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Isotopic labeling of recombinant proteins is crucial for studying proteins by liquid state NMR spectroscopy. Nowadays, conventional E. coli-based expression systems like BL21 (DE3) are typically used to express recombinant proteins. Still, the production of isotopically labeled proteins is often costly and time-consuming, and yields are not sufficient enough for structural studies. Here, we present Vibrio natriegens (Vmax) as an alternative expression system in M9 minimal medium. Due to our optimized M9 minimal medium and conditions and the early time point of induction, we obtained a 2- to 4-fold higher protein yield for two test proteins, FKBP and EYFP, compared to E. coli BL21 (DE3). Production of proteins in V. natriegens in minimal medium is not only more cost-effective and convenient but also less time-consuming than in E. coli. Comparing 15N HSQC spectra of FKBP and EYFP expressed in Vmax and BL21 (DE3) revealed correct folding during expression.

Tomato yield under organic fertilization and supplementation with mineral fertilizersThe influence of fertilization with poultry litter associated or not with mineral fertilization was studied on tomato yield and its components. Two experiments were carried out under field conditions in Epagri -Experimental Station of Caçador, Santa Catarina state, Brazil, during the 2006/07 and 2007/08 seasons in no-tillage system of randomized blocks design, in factorial 4x2, with four rates of poultry litter (0, 4, 8 and 12 t ha -1 , at season 2006/07, and 0, 6, 12 and 18 t ha -1 , at season 2007/08), and the complementation or not of mineral fertilization. The mineral fertilization treatments were done in order to achieve the recommended amounts for each area. The total, marketable, extra AA and extra A fruits yield, the average mass of marketable, extra AA and extra A fruits, and the nutrient content in the leaf diagnoses were evaluated. The application of the organic manure alone was not sufficient to obtain the highest yield of fruits. The amount of organic fertilizer to achieve maximum marketable fruit yield (86.9 t ha -1 ) was estimated to 16.2 t ha -1 . The higher marketable yields (100.1 t ha -1 ) were obtained with the application of mineral fertilizer only or with all doses of organic manure supplemented with mineral fertilizer.