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11.
Achim Raab 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1970,68(3):272-275
Summary The present method permits rapid and sensitive study of the concentration levels of serotonin (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) in the same tissue sample and the determination of the turnover of these substances in small brain parts.I wish to thank Merck Sharp and Dohme for supplies of probenecid. 相似文献
12.
13.
Classification and nomenclature of all human homeobox genes 总被引:2,自引:0,他引:2
Background
The homeobox genes are a large and diverse group of genes, many of which play important roles in the embryonic development of animals. Increasingly, homeobox genes are being compared between genomes in an attempt to understand the evolution of animal development. Despite their importance, the full diversity of human homeobox genes has not previously been described.Results
We have identified all homeobox genes and pseudogenes in the euchromatic regions of the human genome, finding many unannotated, incorrectly annotated, unnamed, misnamed or misclassified genes and pseudogenes. We describe 300 human homeobox loci, which we divide into 235 probable functional genes and 65 probable pseudogenes. These totals include 3 genes with partial homeoboxes and 13 pseudogenes that lack homeoboxes but are clearly derived from homeobox genes. These figures exclude the repetitive DUX1 to DUX5 homeobox sequences of which we identified 35 probable pseudogenes, with many more expected in heterochromatic regions. Nomenclature is established for approximately 40 formerly unnamed loci, reflecting their evolutionary relationships to other loci in human and other species, and nomenclature revisions are proposed for around 30 other loci. We use a classification that recognizes 11 homeobox gene 'classes' subdivided into 102 homeobox gene 'families'.Conclusion
We have conducted a comprehensive survey of homeobox genes and pseudogenes in the human genome, described many new loci, and revised the classification and nomenclature of homeobox genes. The classification scheme may be widely applicable to homeobox genes in other animal genomes and will facilitate comparative genomics of this important gene superclass. 相似文献14.
Goldberg E. Grace Raab Ted K. Desalles Paul Briggs Amy A. Dunbar Robert B. Millero Frank J. Woosley Ryan J. Young Hillary S. Micheli Fiorenza Mccauley Douglas J. 《Coral reefs (Online)》2019,38(2):347-357
Coral Reefs - Bolbometopon muricatum are ecologically unique mega-consumers in coral reef ecosystems. They primarily divide their dietary intake between living scleractinian corals and coral rock,... 相似文献
15.
Intraganglionic laminar endings (IGLEs) represent the only vagal mechanosensory terminals in the tunica muscularis of the esophagus and may be involved in local reflex control. We recently detected extensive though not complete colocalization of the vesicular glutamate transporter 2 (VGLUT2) with markers for IGLEs. To elucidate this colocalization mismatch, this study aimed at identifying markers for nitrergic, cholinergic, peptidergic, and adrenergic neurons and glial cells, which may colocalize with VGLUT2 outside of IGLEs. Confocal imaging revealed, besides substantial colocalization of VGLUT2 and substance P (SP), no other significant colocalizations of VGLUT2 and immunoreactivity for any of these markers within the same varicosities. However, we found close contacts of VGLUT2-positive structures to vesicular acetylcholine transporter, choline acetyltransferase, neuronal nitric oxide synthase, galanin, neuropeptide Y, and vasoactive intestinal peptide immunoreactive cell bodies and varicosities, as well as to glial cells. Neuronal perikarya were never positive for VGLUT2. Thus, VGLUT2 was almost exclusively found in IGLEs and may serve as a specific marker for them. In addition, many IGLEs also contained SP. The close contacts established by IGLEs to myenteric cell bodies, dendrites, and varicose fibers suggest that IGLEs modulate various types of enteric neurons and vice versa. 相似文献
16.
The nature of arsenic-phytochelatin complexes in Holcus lanatus and Pteris cretica 总被引:7,自引:0,他引:7 下载免费PDF全文
We have developed a method to extract and separate phytochelatins (PCs)-metal(loid) complexes using parallel metal(loid)-specific (inductively coupled plasma-mass spectrometry) and organic-specific (electrospray ionization-mass spectrometry) detection systems-and use it here to ascertain the nature of arsenic (As)-PC complexes in plant extracts. This study is the first unequivocal report, to our knowledge, of PC complex coordination chemistry in plant extracts for any metal or metalloid ion. The As-tolerant grass Holcus lanatus and the As hyperaccumulator Pteris cretica were used as model plants. In an in vitro experiment using a mixture of reduced glutathione (GS), PC(2), and PC(3), As preferred the formation of the arsenite [As((III))]-PC(3) complex over GS-As((III))-PC(2), As((III))-(GS)(3), As((III))-PC(2), or As((III))-(PC(2))(2) (GS: glutathione bound to arsenic via sulphur of cysteine). In H. lanatus, the As((III))-PC(3) complex was the dominant complex, although reduced glutathione, PC(2), and PC(3) were found in the extract. P. cretica only synthesizes PC(2) and forms dominantly the GS-As((III))-PC(2) complex. This is the first evidence, to our knowledge, for the existence of mixed glutathione-PC-metal(loid) complexes in plant tissues or in vitro. In both plant species, As is dominantly in non-bound inorganic forms, with 13% being present in PC complexes for H. lanatus and 1% in P. cretica. 相似文献
17.
Nafe R Herminghaus S Raab P Wagner S Pilatus U Schlote W Zanella F Lanfermann H 《Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology》2003,25(3):131-138
OBJECTIVE: To investigate possible statistical correlations between metabolic data from preoperative proton magnetic resonance spectroscopy (1HMRS) and morphology of proliferating tumor cell nuclei in anaplastic gliomas and glioblastomas. STUDY DESIGN: Ki-67-positive tumor cell nuclei in paraffin sections of surgical specimens from 36 patients (7 anaplastic gliomas, World Health Organization grade 3; 29 glioblastomas, World Health Organization grade 4) were investigated by means of a digital image analysis system. Stringent inclusion criteria were formulated for all cases with respect to histologic quality and spectroscopic examination. As morphometric variables, nuclear area, shape variables (roundness factor, size-invariate Fourier amplitudes) and density of Ki-67-positive tumor cell nuclei per reference area were determined. RESULTS: Correlation analysis according to Spearman revealed a significant positive correlation between the total creatine (TCR) peak and nuclear area (P = .005). This correlation was also found within the glioblastoma group (P = .019). There was also a significant negative correlation of nuclear area with the ratio between choline and TCR in all cases (P = .014) and within the glioblastoma group (P = .046). No significant correlation of spectroscopic data was found with nuclear shape or density of Ki-67-positive tumor cell nuclei. CONCLUSION: The results demonstrate a correlation between spectroscopic data and morphology of proliferating tumor cell nuclei (nuclear size) in high grade gliomas. This study is part of a detailed investigation of the interrelationship between preoperative 1HMRS and quantitative histomorphology of gliomas. 相似文献
18.
Tautomerism of 4-hydroxy-2,5-dimethyl-3(2H)-furanone: evidence for its enantioselective biosynthesis
Chiral natural flavor compounds exhibit characteristic enantiomeric excesses due to stereoselective, enzymatically catalyzed reactions during biogenesis. Although the enzymatic formation of the strawberry key flavor compound 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF; Furaneol(R)) is anticipated, the naturally occurring compound is racemic. As racemization due to keto-enol-tautomerism of HDMF could account for this observation, HDMF was investigated by (1)H-NMR spectroscopy tracing the exchange of the proton bound to the furanone-ring at C2 with deuteron from the medium (D(2)O). In addition, the racemization rate of HDMF was directly determined by cyclodextrin-modified capillary electrophoresis of enantiomerically enriched HDMF stored at different pH values. Tautomerism and the racemization rate of HDMF was lowest at pH values between 4 and 5. However, tautomerism and thus racemization was catalyzed under stronger acidic conditions (pH 2) and especially at pH values greater than 7, the value published for plant cell cytosol. Approximately 50% of the protons at C2 were exchanged with deuteron within 1 h at pH 7.2. Therefore, in order to demonstrate the enzymatic formation of HDMF, incubation experiments with Zygosaccharomyces rouxii as well as strawberry protein extract were carried out under slightly acidic conditions (pH 5), the most suitable pH value for studies on the enantiomeric ratio of HDMF. In both experiments the formation of enantiomerically enriched HDMF could be demonstrated for the first time, whereas incubation experiments under neutral conditions resulted in the detection of racemic HDMF. 相似文献
19.
Characterization of terminal NeuNAcalpha2-3Galbeta1-4GlcNAc sequence in lipooligosaccharides of Neisseria meningitidis 总被引:1,自引:0,他引:1
Group B and C Neisseria meningitidis are the major cause of meningococcal
disease in the United States and in Europe. N . meningitidis
lipooligosaccharide (LOS), a major surface antigen, can be divided into 12
immunotypes of which L1 through L8 were found among Group B and C
organisms. Groups B and C but not Group A may sialylate their LOSs with
N-acetylneuraminic acid (NeuNAc) at the nonreducing end because they
synthesize CMP-NeuNAc. Using sialic acid-galactose binding lectins as
probes in an ELISA format, six of the eight LOS immunotypes (L2, L3, L4,
L5, L7, and L8) in Groups B and C bound specifically to Maackia amurensis
leukoagglutinin (MAL), which recognizes NeuNAcalpha2- 3Galbeta1-4GlcNAc/Glc
sequence, but not to Sambucus nigra agglutinin, which binds
NeuNAcalpha2-6Gal sequence. The combination of SDS-PAGE and MAL-blot
analyses revealed that these six LOSs contained only the
NeuNAcalpha2-3Galbeta1-4GlcNAc trisaccharide sequence in their 4.1 kDa LOS
components, which have a common terminal lacto-N-neotetraose (LNnT,
Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc) structure when nonsialylated as shown
by previous studies. The LOS-lectin binding was abolished when the LOSs
were treated with Newcastle disease viral neuraminidase which cleaves
alpha2-->3 linked sialic acid. Methylation analysis of a representative
LOS (L2) confirmed that NeuNAc is 2-->3 linked to Gal. Thus, these LOSs
structurally mimic certain glycolipids, i.e., paragloboside (LNnT-ceramide)
and sialylparagloboside and some glycoproteins in having LNnT and
N-acetyllactosamine sequences, respectively, with or without alpha2-->3
linked NeuNAc. The molecular mimicry of the LOSs may play a role in the
pathogenesis of N.meningitidis by assisting the organism to evade host
immune defenses in man.
相似文献
20.
Andrea Raab Peter Brtter 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1998,707(1-2)
A suitable procedure was developed for speciation analysis of metalloprotein complexes in serum using directly coupled size-exclusion chromatography and an element-specific detector. Two column matrices used for size-exclusion chromatography (TSK G 3000 SW and Asahipak GS 520) were investigated with respect to the recovery and retention behaviour for metalloprotein complexes. Optimisation of the separation parameters (buffer type, concentration, pH) was achieved by means of metalloprotein complexes marked with radiotracers. For speciation of serum the matrix in the Asahipak GS column is more efficient. Given optimal eluent characteristics (100 mM Tris, pH 7.4) the recovery of the elements investigated (sodium, calcium, iron and zinc) was 100%. Further, the retention behaviour (retention time, ratios of the peak areas) remained unchanged for several successive separations. 相似文献