Choline-Containing Compounds in Human Astrocytomas Studied by 1H NMR Spectroscopy In Vivo and In Vitro

Abstract: We have studied 14 patients with different grades of astrocytomas using ¹H NMR spectroscopy in vivo. Typically, astrocytomas exhibited a low N -acetyl-aspartate peak, a prominent signal from choline group-containing compounds, and lactate in the ¹H NMR spectra in vivo. The uncorrected choline/creatine + phosphocreatine peak area ratios were higher in tumors than in normal brain tissue. Absolute concentration of choline-containing compounds (1.74 ± 0.09 mmol/L) in the normal brain tissue was not different in any grade of astrocytoma, but total creatine concentration in healthy brain (7.49 ± 0.30 mmol/L) was higher than that in grade IV astrocytomas (4.84 ± 0.89 mmol/L). Relaxation constants of choline-containing compounds did not differ in tumors from those determined in normal brain. Perchloric acid extracts of biopsy samples from 35 astrocytomas and 13 samples of normal temporal white matter were analyzed with ¹H NMR. Total concentration of choline-containing compounds did not differ between controls and any grade of astrocytoma when the quantification was done in vitro. It is interesting that phosphorylcholine concentration was about twofold greater in grade IV astrocytomas than in controls or other grades of astrocytomas. We conclude that high phosphorylcholine in grade IV astrocytomas may be an indicator of degree of malignancy. The proportional changes within the group of choline-containing compounds observed in vitro were not reflected in the NMR properties of choline signal in vivo.     

Muscle strength and mineral densities in the mandible

Bone mineral density (BMD) in the femoral neck and lumbar spine was measured for 355 postmenopausal 48- to 56-year-old women and the BMD in five different regions in the mandible for 77. All 355 women were also classified according to the size of the masseter muscle. Both skeletal measures and the BMD of the buccal cortex distally from the foramen mentale were compared with the size of the masseter muscle. This study indicates that functional stress, caused by the masseter muscle, is involved in maintaining bone mineral density in edentulous regions of the mandible. Those individuals who are physically active or are bruxists may lose less mineral, after extractions of teeth, from those regions of the jaw bones where the muscles are attached.     

Cloning of cDNA coding for dihydroflavonol-4-reductase (DFR) and characterization of dfr expression in the corollas of Gerbera hybrida var. Regina (Compositae)

We are approaching corolla differentiation in Compositae by studying the regulation of flavonoid pathway genes during inflorescence development in gerbera. We have cloned a dfr cDNA from a ray floret corolla cDNA library of Gerbera hybrida var. Regina by a PCR technique based on homologies found in genes isolated from other plant species. The functionality of the clone was tested in vivo by complementing the dihydrokaempferol accumulating petunia mutant line RL01. By Southern blot analysis, G. hybrida var. Regina was shown to harbour a small family of dfr genes, one member of which was deduced to be mainly responsible for the DFR activity in corolla. Dfr expression in corolla correlates with the anthocyanin accumulation pattern: it is basipetally induced, epidermally specific and restricted to the ligular part of corolla. By comparing the dfr expression in different floret types during inflorescence development, we could see that dfr expression reflects developmental schemes of the outermost ray and trans florets, contrasted with that of the disc florets.     

Cell-mediated immunity in human acute myeloblastic leukemia

Summary Lymphocyte stimulation tests with autologous myeloblasts were performed in 31 patients with nonlymphatic acute leukemia. Twenty-five patients were receiving chemotherapy combined with immunotherapy; six received chemotherapy only. Thirteen nonleukemic patients with various disorders and six healthy control patients were also studied.It was found that 4/15 patients in 9/38 tests had autologous lymphocytes stimulated by autologous circulating myeloblasts. Bone marrow cells also effected stimulation, significantly more often if the marrow was taken in relapse than when it was taken in remission.However, so-called immunotherapy with allogeneic leukemic myeloblasts and BCG could not be shown to increase these frequencies. Nor did it significantly increase the degree of stimulation measured as DNA synthesis in lymphocytes.Moreover, nonleukemic bone marrow cells from patients with other disorders also stimulated autologous lymphocytes in 1/13 patients. No recognition of autologous myeloblasts was observed when the responding lymphocytes were taken in incomplete remission or during the month preceding relapse.with the technical assistance of T. Lehtinen and A. M. SjögrenSupported by the Swedish Cancer Research Foundation Grant no. 699-B76-04XA     

Replacement of natural polyamines by cadaverine and its aminopropyl derivatives in Ehrlich ascites carcinoma cells

Ehrlich ascites carcinoma cells were cultured in the presence of difluoromethyl ornithine (DFMO) and micromolar concentrations of cadaverine for several months. This treatment resulted in a complete disappearance of putrescine and spermidine and reduced spermine content to traces of its normal content. The natural polyamines were replaced by cadaverine (about 40% of total polyamines), N-(3-aminopropyl)cadaverine (about 50%) and N,N′-bis(3-aminopropyl)cadaverine (about 5%). In comparison with untreated cells or cells grown in the presence of DFMO and putrescine, the “cadaverine cells” grew definitely slower, their protein synthesis was depressed while DNA and RNA syntheses proceeded at near normal rate. In spite of the high intracellular concentrations of cadaverine and its aminopropyl derivatives, the tumor cells grown in the presence of DFMO and cadaverine, behaved exactly like cells severly depleted of putrescine and spermidine. Though exposed to DFMO, ornithine decarboxylase activity was almost 10 times higher than that in untreated cells. S-Adenosyl-L-methionine decarboxylase activity was likewise strikingly elevated, and these cells transported methylglyoxal strikingly elevated, and these cells transported methylglyoxal bis(guanylhydrazone) (MGBG) at a rate that was more than 5 times faster than that in untreated cells. Furthermore, these cells exhibited arginase activity, which was less than one fifth of that found in untreated cells.     

cDNA sequence of a Drosophila melanogaster gene, Dfur1, encoding a protein structurally related to the subtilisin-like proprotein processing enzyme furin

Screening a genomic library of Drosophila melanogaster DNA with a human fur cDNA probe resulted in the isolation of DNA clones that apparently belonged to two different DNA regions of the Drosophila genome. Subsequently, corresponding Drosophila cDNA clones were isolated. Nucleotide sequence analysis indicated that these cDNA clones originated from two different genes, which were called Dfur1 and Dfur2. From overlapping Dfur1 cDNA clones, a composite cDNA could be constructed and analysis of its nucleotide sequence revealed the coding sequence for a protein of 899 amino acid residues. This protein, designated Dfurin1, exhibited striking sequence homology to human furin and contained the same protein domains except for the cysteine-rich region. Furthermore, unlike human furin, Dfurin1 possessed an extended amino-terminal region in which a potential transmembrane anchor was present.     

Interaction with functional membrane proteins--a common mechanism of toxicity for lipophilic environmental chemicals?

1. The effects of several phenols, anilines and aliphatic alcohols on yeast plasma membrane H(+)-ATPase and purine transport system as well as on Na+, K(+)-ATPase and adenosine uptake by Chinese hamster ovary cells (CHO) were investigated. 2. In all cases an inhibition was observed, which could be correlated with the octanol/water partition coefficients of the substances tested, thus making quantitative structure-activity predictions possible. 3. The observed effects correlated well with the influence of the chemicals on cell growth. 4. The results suggest a common mechanism of toxicity by the action of hydrophobic xenobiotics on biomembranes.     

Chromosomal deletion 4p15.32----p14 in a Treacher Collins syndrome patient: exclusion of the disease locus from and mapping of anonymous DNA sequences to this region.

Treacher Collins syndrome is an autosomal dominant condition of bilateral craniofacial abnormalities of structures derived from the first and second branchial arches. A patient with severe manifestations of Treacher Collins syndrome and a de novo chromosomal deletion in region 4p15.32----p14 was identified. Anonymous DNA sequences of loci D4S18, D4S19, D4S20, D4S22, and D4S23 were mapped to the deleted region. DNA probes previously mapped to loci on chromosome 4p (D4S10, D4S15, D4S16, D4S26, D4S35, D4S95, D4S144, RAF1P1, QDPR, and HOX7) were not deleted in this patient. Linkage analysis between the D4S18, D4S23, and QDPR loci and Treacher Collins syndrome in eight families excluded the Treacher Collins syndrome locus from the region of the deletion.     

Andean and California condors possess dissimilar genetic composition but exhibit similar demographic histories

While genetic diversity of threatened species is a major concern of conservation biologists, historic patterns of genetic variation are often unknown. A powerful approach to assess patterns and processes of genetic erosion is via ancient DNA techniques. Herein, we analyzed mtDNA from historical samples (1800s to present) of Andean Condors (Vultur gryphus) to investigate whether contemporary low genetic variability is the result of recent human expansion and persecution, and compared this genetic history to that of California condors (Gymnogyps californianus).We then explored historic demographies for both species via coalescent simulations. We found that Andean condors have lost at least 17% of their genetic variation in the early 20th century. Unlike California condors, however, low mtDNA diversity in the Andean condor was mostly ancient, before European arrival. However, we found that both condor species shared similar demographies in that population bottlenecks were recent and co‐occurred with the introduction of livestock to the Americas and the global collapse of marine mammals. Given the combined information on genetic and demographic processes, we suggest that the protection of key habitats should be targeted for conserving extant genetic diversity and facilitate the natural recolonization of lost territories, while nuclear genomic data should be used to inform translocation plans.