I-region restriction of alloantigen recognition: alloantigen expressed on the surface of a hybridoma cell must be presented in the context of self class II major histocompatibility complex determinants for recognition by a dual-reactive T-cell clone

A helper-T-lymphocyte clone, designated A10, proliferated in response to both hen egg ovalbumin (OVA) presented in the context of self I-Ak and to the alloantigen I-As. The alloantigen source could be provided by irradiated H-2s spleen cells and also by paraformaldehyde-fixed H-2s spleen cells. However, for fixed allogeneic spleen cells to stimulate proliferation of the cloned cells, it was necessary to add irradiated syngeneic I-Ak-bearing spleen cells, as fixed H-2s spleen cells added, by themselves, to A10 cells were nonstimulatory. We have extended these findings by generating a monoclonal hybridoma cell which expressed the I-As allodeterminant. Similar to our results with fixed allogeneic spleen cells, this source of alloantigen could stimulate A10 cells to proliferate only if irradiated syngeneic spleen cells were added to the cultures. These proliferative responses were effectively inhibited by anti-I-Ak monoclonal antibody (mAb) and by anti-I-As mAb. Furthermore, the response of A10 cells to the alloantigen-bearing hybridoma cells were also inhibited by the anti-L3T4 mAb GK1.5. Collectively, these data indicate that, in some situations, alloreactivity may be mediated by self class II major histocompatibility complex restriction of alloantigen-driven proliferation.     

Differential regulation of the brain and gut immunoreactive dynorphin by the serotonin system

Administration of drugs such as fenfluramine, 20-40 mg/kg, and m-chlorophenylpiperazine (m-CPP), 2.5-5 mg/kg, which release serotonin or activate postsynaptic serotonin receptors, respectively, induced a dramatic decrease in the duodenal content of immunoreactive dynorphin (ir-DYN). The effect was antagonized by cyproheptadine, 1 mg/kg. Similarly, acute administration of the specific serotonin reuptake blockers fluvoxamine, 15 mg/kg, or femoxetine, 10 mg/kg, and 5-hydroxytryptophan (5-HTP), 40-160 mg/kg, evoked a marked decrease in the duodenal content of ir-DYN. A combined administration of fluvoxamine or femoxetine and 5-HTP failed to potentiate the effect of individual treatment. Only a higher dose of fenfluramine, 40 mg/kg, increased the ir-DYN content in the hypothalamus. These results suggest that the brain and gut ir-DYN is independently regulated by the serotonin system and that a serotonin mechanism might stimulate release of the gut dynorphin content.     

Relation between macronuclear DNA and total protein content and generation time in thechilodonella steini (Ciliata) sister cells

Summary Using the monotone dependence function (mdf) together with correlation coefficient it was found that the Ma-DNA content as well as total protein content are regularly, linearly, positively and strongly dependent in sister cells (proter-opisthe) ofChilodonella steini. Additionally it was shown that proter-opisthe ordering is irrelevant to Ma-DNA and protein contents.Analysis of sister cell generation times (TG) confirmed the existence of regular, linear, positive and strong codependence.The relations between Ma-DNA and total protein contents, between protein content and TG, and between Ma-DNA content and TG were also described. There is a weak, linear dependence between Ma-DNA and total protein contents. Relations of TG and Ma-DNA content or TG and total protein content are non-linear and not even monotone. Low and high levels of DNA or proteins are connected with long generation times.     

Structural and functional analysis of the respiratory burst in the phagocytosing macrophage

The interrelation between structural changes and oxygen consumption by the phagocyting macrophage was studied. The mean number of phagocyted particles was estimated by the method of stereological transformation. It is found that the uptake of yeast particles and CN- -nonsensitive oxygen consumption is related to the concentration of yeast cells in the incubation medium. A positive correlation was established between the oxygen consumption and the mean number of phagocyted particles. The results obtained may suggest that the "respiration burst" takes place in the contact area of the macrophage and the phagocyted material, and its extent probably depends on the surface of that contact area.     

Characterization and evolution of a single-copy sequence from the human Y chromosome.

To study the evolution and organization of DNA from the human Y chromosome, we constructed a recombinant library of human Y DNA by using a somatic cell hybrid in which the only cytologically detectable human chromosome is the Y. One recombinant (4B2) contained a 3.3-kilobase EcoRI single-copy fragment which was localized to the proximal portion of the Y long arm. Sequences homologous to this human DNA are present in male gorilla, chimpanzee, and orangutan DNAs but not in female ape DNAs. Under stringent hybridization conditions, the homologous sequence is either a single-copy or a low-order repeat in humans and in the apes. With relaxed hybridization conditions, this human Y probe detected several homologous DNA fragments which are all derived from the Y in that they occur in male DNAs from humans and the apes but not in female DNAs. In contrast, this probe hybridized to highly repeated sequences in both male and female DNAs from old world monkeys. Thus, sequences homologous to this probe underwent a change in copy number and chromosomal distribution during primate evolution.     

Structure and localization of genes encoding aberrant and normal epidermal growth factor receptor RNAs from A431 human carcinoma cells.

A431 cells have an amplification of the epidermal growth factor (EGF) receptor gene, the cellular homolog of the v-erb B oncogene, and overproduce an aberrant 2.9-kilobase RNA that encodes a portion of the EGF receptor. A cDNA (pE15) for the aberrant RNA was cloned, sequenced, and used to analyze genomic DNA blots from A431 and normal cells. These data indicate that the aberrant RNA is created by a gene rearrangement within chromosome 7, resulting in a fusion of the 5' portion of the EGF receptor gene to an unidentified region of genomic DNA. The unidentified sequences are amplified to about the same degree (20- to 30-fold) as the EGF receptor sequences. In situ hybridization to chromosomes from normal cells and A431 cells show that both the EGF receptor gene and the unidentified DNA are localized to the p14-p12 region of chromosome 7. By using cDNA fragments to probe DNA blots from mouse-A431 somatic cell hybrids, the rearranged receptor gene was shown to be associated with translocation chromosome M4.     

“同时蒸馏-萃取”分析茉莉花香成分

用一种经过改进的“同时蒸馏-萃取”仪提取了茉莉花的香成分,以 GC/MS 和 Kovats保留指数法鉴定了提取物中的28个化学成分。主要成分为:芳樟醇、乙酸苯甲酯、顺-石竹萜烯、榧烯醇、苯甲酸顺-3-己烯酯、邻氨基苯甲酸甲酯、二十三烯-11及吲哚。讨论了鲜花香成分和植物精油的采集与分析方法。     

Elemental composition of the human atherosclerotic artery wall

Summary The elemental composition of the human atheroselerotic popliteal artery was examined using the proton-induced X-ray-emission (PIXE) method. The application of a narrow proton beam (3×10 m²) enabled us to determine not only the concentrations of Cl, K, Ca, Fe, Cu, Zn, Br and Pb, but also their localization in different artery-wall regions. The highest mean concentrations of Cl, K, Zn and Br were found in the tunica media. In the investigated sections the distribution of Ca and Fe varied: sometimes, these elements were prevalent in the tunica intima, whereas in other cases, the highest concentrations were observed in the tunica media or tunica adventitia. The concentration profiles of each element were characterized by many sharp, narrow peaks. The highest concentrations of Ca and Fe showed such high levels that only one explanation is possible, i.e. the presence of crystals. The correlation of Ca peaks with those of Zn and Fe is discussed. The usefulness of the micro-PIXE method for the investigation of biomedical materials is also considered.     

新疆20种药用植物的染色体观察

本文对在新疆生长和引种栽培的10科20种药用植物染色体进行了计数和研究,其中5种进行了核型分析,6种为首次报道。