Interleukin-1-β and Tumor Necrosis Factor-α Increase Peripheral-Type Benzodiazepine Binding Sites in Cultured Polygonal Astrocytes

Peripheral-type benzodiazepine binding sites (PTBBS) are markedly increased in the injured CNS. Astrocytes appear to be the primary cell type which express increased PTBBS. Because certain cytokines within the injured CNS are potent mitogens for astrocytes, we examined the effects of two such cytokines, interleukin (IL)-1 beta and tumor necrosis factor (TNF), on PTBBS in cultured astrocytes using [3H]Ro 5-4864 as the specific ligand. Purified cultures of either polygonal or process-bearing astrocytes were prepared from neonatal rat cerebral hemispheres. At a concentration of 1.8 nM, specific binding of the radioactive ligand to polygonal astrocytes reached equilibrium within 60 min and was half-maximal by 5-10 min. By contrast, specific binding to process-bearing astrocytes barely exceeded background levels. IL-1 and TNF increased PTBBS within polygonal astrocytes in both dose- and time-dependent manners. At 10-50 ng/ml, IL-1 beta and TNF-alpha elevated [3H]Ro 5-4864 binding in polygonal astrocyte cultures 65 and 87%, respectively, above the level in control cultures. However, no changes in PTBBS were seen within polygonal astrocytes after IL-2 treatment. Scatchard analysis of saturation binding experiments suggested that the increase in PTBBS promoted by TNF was due to an increased number of binding sites present in polygonal astrocytes and not due to an increase in receptor affinity. Binding data suggested that PTBBS within cultures of process-bearing astrocytes were virtually absent irrespective of the treatment. These in vitro data suggest that certain cytokines found in the injured brain may be involved in up-regulating PTBBS within a particular subtype of astrocyte.     

Synthesis and Analysis of Nucleosides Bearing Pyrrolepolyamide Binding to DNA

Abstract

An efficient synthesis of adenosine bearing pyrrolepolyamide 1 was achieved by coupling of 3 with 2. The CD spectra obtained at several [ligand ]/[duplex] ratios allowed verification of the formation complex of the DNA duplex [d(CGCAAATTGGC)/d(GCCAATTTGCG)] with 1.     

Localization of vanadium-containing particles in the lungs of uranium/vanadium miners

Several geological formations of the Utah-Colorado mining region mined for uranium ore during and after World War II had been mined earlier for vanadium. Therefore, most miners and millers from that region were exposed to those metals’ ores or tailings at one time or another. Preliminary investigation to determine uranium and vanadium retained in the lungs of a former uranium miner and miller from this region, who died of lung cancer (mesothelioma), showed a high nonuniform distribution of vanadium. This observation led to the hypothesis that the vanadium content in the lungs could be associated with inhaled particles. Further examination of spectra of characteristic X-rays obtained by scanning particle-induced X-ray emission (microPIXE) of an autopsy sample of this lung indicated that vanadium was indeed present in localized sites within the 20-μm spatial resolution of the proton beam. This work points out that the microPIXE-RBS (Rutherford backscattering) test for vanadium can be used for site localization of inhaled particles retained in the lungs. Further studies are in progress to: (i) locate uranium-bearing particles in lung tissues of former uranium miners and millers; and (ii) evaluate the local doses of alpha radiation received from these particles.     

The potential for rust infection to cause natural selection in apomictic Arabis holboellii (Brassicaceae)

Few studies have examined the potential for pathogens with complex life cycles to cause selection on their required alternate (=intermediate) hosts. Here we examine the effects of two fungal pathogens on an herbaceous mustard, Arabis holboellii. One pathogen species uses A. holboellii as a primary host, the other uses it as an alternate host. This plant-pathogen system is especially interesting because the host, A. holboellii, is apomictic; thus individuals reproduce exact copies of themselves. Despite this mode of reproduction, A. holboellii populations are surprisingly genetically diverse. Could frequency dependent selection by pathogens be maintaining clonal diversity? This study assesses the potential for selection by pathogens. In a controlled greehouse experiment we show that there is heritable variation in A. holboellii's resistance to the rust, Puccinia monoica, and that host fitness is severely reduced by P. monoica infection in both the greenhouse and under natural conditions. Field observations indicate that host clones are also differentially susceptible to the short-cycled rust, P. thlaspeos, and that host fitness is reduced by infection to this pathogen as well. Although the preconditions for pathogen-mediated selection are present, frequency-dependent selection by pathogens is unlikely to be important in structuring populations of Arabis holboellii because multiple host genotypes are susceptible to the same inoculum and the pathogen has a long generation time.     

Investigating hypothetical products from noncoding frames (HyPNoFs)

Hypothetical Products from Noncoding Frames (i.e., HyPNoFs) are hypothetical, not-coded proteins, translated from alternate reading frames (i.e., coding+1 and coding+2) of cDNAs. HyPNoFs of CD4, PKC, oncostatin, bcl-2 proto-oncogene, tumor suppressor p53, cystic fibrosis transmembrane regulator (CFTR), and tumor necrosis factors a and were searched as query sequences vs the SWISS-PROT data bank. Homology searches carried out revealed that hypothetical products (i.e., HyPNoFs) may share high similarity with real protein products actually coded. Sequence similarity of hypothetical products to real proteins is sometimes very high, suggesting common conformational features, according to the Sander and Schneider cutoff value. This finding supports the hypothesis that eukaryotic DNA, currently considered to be monocistronic, might occasionally have polycistronic regions, carrying different protein messages on overlapping frames. As yet, polycistronic genes have been observed in viral genomes only. The presence of polycistronic regions in eukaryotic genes is likely reminiscent of an ancient strategy, rather than a present feature of the genome in eukaryotes.These data suggest that thorough investigation of HyPNoFs is likely to improve our ability to trace genes' evolution and to investigate structure-function relationships of protein and DNA sequences.     

The restoration of the T-lymphoid system of nude mice: lower efficiency of nonlymphoid, epithelial thymus grafts.

The T-cell deficiency of nude mice is due to an abnormal differentiation of the thymus epithelium; it can be persistently corrected by grafting a neonatal thymus. However, grafted adult thymuses or epithelial thymuses are not repopulated by large numbers of host-derived lymphocytes, as is the case when a whole neonatal thymus is grafted. Furthermore, the repopulation of the spleen and lymph nodes by T cells is less pronounced than after whole neonatal thymus transplantation, and the restoration of the reactivity to T-cell mitogens is irregular. Therefore, the integrity and the age of the thymus graft are important for a good restoration of the T-lymphoid system of congenitally athymic animals.     

城市尺度的城乡建设用地潜力及空间格局匹配评价——以南昌市为例

随着经济快速发展和城镇化进程不断加快,土地开发强度日益增大,导致生态环境不断恶化,分析城乡建设用地承载能力及空间格局匹配情况,对解决土地利用不合理、生态破坏等问题具有重要意义。以江西省南昌市为例,首先从生态安全、自然条件、社会经济等方面构建指标体系,采用层次分析法和限制系数评价模型,进行城乡建设用地开发适宜性评价,然后测算城乡建设用地承载力、可承载城乡建设用地丰度;最后与现状城乡建设用地进行空间匹配度分析,并探讨可承载临界值、丰度与空间匹配度的相关性。结果表明：南昌市城乡建设用地最适宜区、较适宜区、较不适宜区和不适宜区面积分别为1466.19、1346.01、353.69 km²和3770.70 km²;研究区城乡建设用地可承载临界值和可承载潜力分别为41.25%和24.05%,各县（区）值差异较大,各县（区）可承载临界值和可承载潜力范围分别为19.43%-98.71%和5.65%-49.83%,可承载城乡建设用地丰度情况良好,各县（区）值介于0.19-1.50之间;研究区各县（区）空间匹配度范围为67.41%-99.25%;相关分析显示,空间匹配度与城乡建设用地可承载临界值和可承载城乡建设用地丰度均呈正相关关系。研究可为南昌市城乡建设用地合理开发利用和国土空间优化提供依据。     

A single lycaenid caterpillar gets an ant‐constructed shelter and uninterrupted ant attendance

Ant‐lycaenid associations range from mutualism to parasitism and the caterpillars of some species of lycaenids are reported to enter ant nests for shelter, diapause, or pupation. The present study aimed to examine the nature of the association between Euchrysops cnejus (Fabricius) (Lepidoptera: Lycaenidae) and Camponotus compressus (Fabricius) (Hymenoptera: Formicidae) worker ants on the extrafloral nectary‐bearing cowpea plant, Vigna unguiculata (L.) Walp. (Fabaceae). The abundance patterns of the ants and the lycaenid caterpillars together with the spatial patrolling patterns of the ants on the plants revealed that ant abundance increased with the occurrence of the lycaenid caterpillars and the ants preferred the lycaenids over the extrafloral nectar. Camponotus compressus worker ants constructed a shelter at the cowpea plant base after interaction with one or more lycaenid caterpillar(s) and tended the caterpillars and pupae till the emergence of the butterfly. The ant‐constructed shelters (ACSs) inhabited by the minor caste workers (13 ± 1.3 ants per ACS), were utilized by the caterpillars to undergo pupation. The ants confined their activities predominantly to tending the pod‐feeding caterpillars and the solitary pupa within each ACS. It appears that the behavior of the tending worker ants is modulated by the lycaenid vulnerable stages.