Three-dimensional reconstruction of cytochrome oxidase vesicle crystals prepared by cholate solubilization

Cytochrome oxidase vesicle crystals with long-range order have been obtained from cholate-solubilized, highly purified reconstitutively active preparations. These crystals, which are suitable for electron-microscopic structure investigation, show pgg symmetry in the 0 degree projection. Using Fourier reconstruction and modified back-projection methods, a three-dimensional reconstruction has been obtained at a resolution of 25 A. Our structural results are in agreement with the model of Henderson et al. [J. Mol. Biol. 112, 631 (1977)] obtained for their Triton-derived crystals.     

Translocation of oncogene c-sis from chromosome 22 to chromosome 11 in a Ewing sarcoma-derived cell line.

Somatic cell hybrids, obtained after fusion of translocation (11;22)-positive Ewing sarcoma cells and Chinese hamster fibroblasts, were assayed for the presence of immunoglobulin C lambda, Philadelphia chromosome breakpoint cluster region, and c-sis oncogene sequences. It was found that c-sis was translocated from chromosome 22 to chromosome 11 in the Ewing sarcoma cells used, indicating that the breakpoint must be proximal to this locus. Moreover, we found that the chromosome 22-linked C lambda and breakpoint cluster region sequences are not translocated. This result confirms an earlier cytogenetic observation that the Ewing sarcoma-associated breakpoint in chromosome 22 is distal to those observed in translocation (8;22)-positive Burkitt lymphoma and in Philadelphia chromosome-positive chronic myeloid leukemia.     

Naturally crystalline porin in the outer membrane of Bordetella pertussis

The Gram-negative bacterium Bordetella pertussis is the agent responsible for whooping-cough, and much interest has focused on the functions, structures and immunological properties of the molecules exposed at its outer surface. We have found by electron microscopy that cells of two strains of B. pertussis are covered with a crystalline surface lattice. This lattice is not an extrinsic layer of high molecular weight glycoproteins, such as occur on many other bacteria, but is a natural crystal of an intrinsic membrane protein of 40,000 Mr. This molecule has been shown to be an anion-selective member of an extensive family of proteins ("porins") that render Gram-negative outer membranes permeable to solutes of up to approximately 650 Mr. Computer image processing reveals a trimeric channel-like structure that closely resembles other porins visualized in artificial arrays after treatment with detergents, but in a novel (p2) crystal form. This correlation provides a "missing link" between earlier structural studies based on artificial arrays of porins (of undefined physiological status), and membrane-permeabilization experiments with solubilized porins (in undefined structural states). For the strains characterized so far, crystallinity of the porin surface lattice shows an intriguing correlation with nonpathogenicity.     

Does nitrogen nutrition restrict the CO2 response of fertile grassland lacking legumes?

The extent of the response of plant growth to atmospheric CO₂ enrichment depends on the availability of resources other than CO₂. An important growth-limiting resource under field conditions is nitrogen (N). N may, therefore, influence the CO₂ response of plants. The effect of elevated CO₂ (60 Pa) partial pressure (pCO₂) on the N nutrition of field-grown Lolium perenne swards, cultivated alone or in association with Trifolium repens, was investigated using free air carbon dioxide enrichment (FACE) technology over 3 years. The established grassland ecosystems were treated with two N fertilization levels and were defoliated at two frequencies. Under elevated pCO₂, the above-ground plant material of the L. perenne monoculture showed a consistent and significant decline in N concentration which, in general, led to a lower total annual N yield. Despite the decline in the critical N concentration (minimum N concentration required for non-N-limited biomass production) under elevated pCO₂, the index of N nutrition (ratio of actual N concentration and critical N concentration) was lower under elevated pCO₂ than under ambient pCO₂ in frequently defoliated L. perenne monocultures. Thus, we suggest that reduced N yield under elevated pCO₂ was evoked indirectly by a reduction of plant-available N. For L. perenne grown in association with T. repens and exposed to elevated pCO₂, there was an increase in the contribution of symbiotically fixed N to the total N yield of the grass. This can be explained by an increased apparent transfer of N from the associated N₂-fixing legume species to the non-fixing grass. The total annual N yield of the mixed grass/legume swards increased under elevated pCO₂. All the additional N yielded was due to symbiotically fixed N. Through the presence of an N₂-fixing plant species more symbiotically fixed N was introduced into the system and consequently helped to overcome N limitation under elevated pCO₂. Received: 11 November 1996 / Accepted: 20 May 1997     

Net soil carbon input under ambient and elevated CO2 concentrations: isotopic evidence after 4 years

Elevation of atmospheric CO₂ concentration is predicted to increase net primary production, which could lead to additional C sequestration in terrestrial ecosystems. Soil C input was determined under ambient and Free Atmospheric Carbon dioxide Enrichment (FACE) conditions for Lolium perenne L. and Trifolium repens L. grown for four years in a sandy‐loam soil. The ¹³C content of the soil organic matter C had been increased by 5‰ compared to the native soil by prior cropping to corn (Zea mays) for > 20 years. Both species received low or high amounts of N fertilizer in separate plots. The total accumulated above‐ground biomass produced by L. perenne during the 4‐year period was strongly dependent on the amount of N fertilizer applied but did not respond to increased CO₂. In contrast, the total accumulated above‐ground biomass of T. repens doubled under elevated CO₂ but remained independent of N fertilizer rate. The C:N ratio of above‐ground biomass for both species increased under elevated CO₂ whereas only the C:N ratio of L. perenne roots increased under elevated CO₂. Root biomass of L. perenne doubled under elevated CO₂ and again under high N fertilization. Total soil C was unaffected by CO₂ treatment but dependent on species. After 4 years and for both crops, the fraction of new C (F‐value) under ambient conditions was higher (P= 0.076) than under FACE conditions: 0.43 vs. 0.38. Soil under L. perenne showed an increase in total soil organic matter whereas N fertilization or elevated CO₂ had no effect on total soil organic matter content for both systems. The net amount of C sequestered in 4 years was unaffected by the CO₂ concentration (overall average of 8.5 g C kg^?1 soil). There was a significant species effect and more new C was sequestered under highly fertilized L. perenne. The amount of new C sequestered in the soil was primarily dependent on plant species and the response of root biomass to CO₂ and N fertilization. Therefore, in this FACE study net soil C sequestration was largely depended on how the species responded to N rather than to elevated CO₂.     

Use of Complementary and Alternative Medicine (CAM) as Part of the Oncological Treatment: Survey about Patients’ Attitude towards CAM in a University-Based Oncology Center in Germany

IntroductionTo understand if and which patients would be open-minded to Complementary and Alternative Medicine (CAM) use parallel to their oncological treatment. Moreover, we sought to determine which methods are most accepted and which are the primary motivators to use CAM.MethodsWe developed and anonymously conducted a questionnaire for patients in the oncology center (TU Munich). Questions focus on different CAM methods, previous experiences, and willingness to apply or use CAM when offered in a university-based setting.ResultsA total of 171 of 376 patients (37.4% women, 62.0% men, 0.6% unknown) participated. This corresponds to a return rate of 45%. Median age was 64 years (17–87 years). Of all participants, 15.2% used CAM during their oncological therapy; 32.7% have used it in the past. The majority (81.9%) was not using CAM during therapy; 55.5% have not used CAM in the past respectively. The analysis revealed a significant correlation between education and CAM use during therapy (r = 0.18; p = 0.02), and CAM use in the past (r = 0.17; p = 0.04). Of all patients using CAM during therapy, favored methods were food supplements (42.3%), vitamins/minerals (42.3%), massage (34.6%). Motivations are especially the reduction of side effect and stress, the positive effect of certain CAM-treatments on the immune system and tumor therapy. Results showed no difference between women and men. Most patients not having had any experience with CAM complain about the deficiency of information by their treating oncologist (31.4%) as well as missing treatment possibilities (54.3%).ConclusionSince many patients believe in study results demonstrating the efficacy of CAM, it stresses our task to develop innovative study protocols to investigate the outcomes of certain CAM on symptom reduction or other endpoints. Thus, prospective trials and innovative evidence-based treatment concepts to include CAM into high-end oncology is what patients demand and what a modern oncology center should offer.     

The human calbindin 27-kDa gene: structural organization of the 5' and 3' regions, chromosomal assignment, and restriction fragment length polymorphism

The 5' and 3' regions of the human gene coding for calbindin 27 kDa were cloned and sequenced. Structural features of the 5' region included the presence of an Alu repeat and two elements regularly associated with eukaryotic promoters: an alternating purine-pyrimidine element and a homopurine-homopyrimidine box. The 3' region contained a second Alu family member and a degenerate 1.4-kb L1 repeat. A comparison with the chicken promoter was made in order to define regions conserved in evolution and potentially important in gene expression regulation. The greater similarity is located around the TATA box, but strongly conserved elements were not found. The gene was assigned to chromosome 8 by using human-rodent hybrid cell lines. Two restriction fragment length polymorphisms (HindIII and SacI) were detected with a cDNA probe recognizing the 3' end of the gene.     

Giant flagellar bundles ofVibrio alginolyticus (NCMB 1803)

Summary Following swarming ofVibrio alginolyticus on solid medium a large number of giant flagellar bundles appear behind the growth front. The suggested sequence of events leading to bundle formation is as follows. After inoculation from liquid to solid media the short rods with a single polar sheathed flagellum develop peritrichous nonsheathed flagella and elongate into long filamentous swarmers. After division into short rods, some of the cells become spherical in shape with many peritrichous flagella concentrated at one pole in close association with the sheathed polar flagellum. These tufted spherical bodies form the template upon which masses of loose peritrichous flagella spontaneously aggregate.Flagellar bundles formed when bacteria are grown at pH 8.5 are longer than those formed at pH 7.2 and shorter when grown at pH 6.5. In distilled water the flagellar bundles disintegrate into masses of flagellar fragments.     

A GDP-fucose:[Gal beta 1----4]GlcNAc alpha 1----3-fucosyltransferase activity is correlated with the presence of human chromosome 11 and the expression of the Lex, Ley, and sialyl-Lex antigens in human-mouse cell hybrids

By fusion of human leukocytes and cells of the murine myeloid cell line WEHI-TG, we produced human-mouse myeloid cell hybrids. Hybrids which contain human chromosome 11 have been demonstrated to express the myeloid-associated carbohydrate antigen Lex (Geurts van Kessel, A. H. M., Tetteroo, P. A. T., Von dem Borne, A. E. G. Kr., Hagemeijer, A., and Bootsma, D. (1983) Proc. Natl. Acad. Sci. U. S. A. 80, 3748-3752). In this paper, we report that the hybrids that contain chromosome 11 also expressed the Lex-related antigens Ley and sialyl-Lex. Glycosyltransferase activities were measured in a panel of six such hybrid cell lines, and the correlation to antigen expression and to the presence of human chromosomes was investigated. GDP-fucose:[Gal beta 1----4]GlcNAc alpha 1----3-fucosyltransferase activity in the hybrids tested correlated with the expression of Lex, Ley, and sialyl-Lex and with the occurrence of chromosome 11. No such correlation was found for several other glycosyltransferases involved in the synthesis of these antigens. These findings suggest that the gene for alpha 3-fucosyltransferase is located on chromosome 11 and that it is through the activity of this enzyme that the expression of Lex, Ley, and sialyl-Lex in human myeloid cells is regulated.