Determination of quantitative parameters of Escherichia coli phagocytosis by mouse peritoneal macrophages

The fluorometric method was used to study guantitative parameters of phagocytosis of fluorescein-labeled Escherichia coli cells by mouse peritoneal macrophages. E. coli cells were conjugated with fluoresceinisothiocyanate (FITC) and then incubated with macrophages. At the end of the assay phagocytosis was arrested with a lysing solution (0.5% Triton X-100 in 0.01 M phosphate-buffered 0.15 M saline, pH 7.4). Trypan blue at a concentration of 0.04% was used as a quenching agent to differentiate between attachment and ingestion of E. coli cells. The time course analysis within this method showed that phagocytosis of E. coli cells was temperature and opsonin dependent. The number of E. coli cells ingested by macrophages increased rapidly during the initial 60 min of incubation at 37 degrees C. E. coli cells required opsonization with 5% native serum to achieve their optimal uptake. The uptake of nonopsonized bacteria by macrophages was significantly lower that that of opsonized ones (P < 0.05). It was demonstrated that sodium azide inhibited phagocytosis of E. coli cells by mouse peritoneal macrophages in a dose-dependent manner.     

抗肿瘤药阿霉素诱导Wnt通路抑制因子的表达

研究抗肿瘤药阿霉素对Wnt通路抑制因子FrpHE(frizzled-related protein)和DKK-1(Dickkopf-1)表达的作用.将抗肿瘤药阿霉素加入到人肝癌HepG2(HepG2,含野生型p53;Hep3B,p53缺失)、人大肠癌(Lovo,含野生型p53)和人神经胶质瘤细胞(U251,p53突变)细胞株中.以RT-PCR技术检测阿霉素对Wnt通路抑制因子FrpHE和DKK-1的表达调节作用,以流式细胞术检测在肿瘤细胞中Wnt通路的关键调节因子β-catenin的表达.在加入阿霉素24h后FrpHEmRNA表达水平在人肝癌细胞(HepG2,含野生型p53;Hep3B,p53缺失)中与对照组相比表达水平显著增加.在人大肠癌细胞(Lovo,含野生型p53)和人神经胶质瘤细胞(U251,p53突变型)细胞中,未见FrpHE mRNA表达.DKK-1mRNA表达水平在人肝癌细胞(HepG2,含野生型p53;Hep3B,p53缺失)、人大肠癌细胞(Lovo,含野生型p53)和人神经胶质瘤细胞(U251,p53突变型)中与对照组相比表达水平显著增加.β-catenin的阳性细胞百分比强度和平均荧光量强度与对照组相比,表达水平降低.提示化疗药阿霉素能明显诱导抑制剂FrpHEmRNA和DKK-1mRNA的表达.     

Checklist of the Caesalpinioideae (Leguminosae) of Equatorial Guinea (Annobón, Bioko and Río Muni)

This study provides a checklist of the Caesalpinioideae (Leguminosae) present in Equatorial Guinea, comprising 52 genera and 124 taxa. Seven species are known from Annobón, 33 from Bioko and 109 from Río Muni. The best represented genus is Senna with eight species. In addition, bibliographic references for Caesalpinioideae (Leguminosae) from Equatorial Guinea have been gathered and checked. Fourteen species are included based on literature records, because their distribution ranges suggest they may occur in Equatorial Guinea, 11 introduced species could be naturalized, and 45 taxa are recorded for the first time from the country. This represents an increase of over 35% in the floristic knowledge of Caesalpinioideae from Equatorial Guinea. A statistical summary is presented at the end of the checklist.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 541–562.     

New epidemiological features on animal trypanosomiasis by molecular analysis in the pastoral zone of Sideradougou, Burkina Faso

A multidisciplinary work was undertaken in the agropastoral zone of Sidéradougou, Burkina Faso to try to elucidate the key factors determining the presence of tsetse flies. In this study the PCR was used to characterize trypanosomes infecting the vector ( Glossina tachinoides and Glossina palpalis gambiensis ) and the host, i.e. cattle. A 2-year survey involved dissecting 2211 tsetse of the two Glossina species. A total of 298 parasitologically infected tsetse were analysed by PCR. Trypanosoma vivax was the most frequently identified trypanosome followed by the savannah type of T. congolense and, to a lesser extent, the riverine forest type of T. congolense , and by T. brucei . No cases of T. simiae were found. From the 107 identified infections in cattle, the taxa were the same, but T. congolense savannah type was more frequent, whereas T. vivax and T. congolense riverine forest types were found less frequently. A correlation was found between midgut infection rates of tsetse, nonidentified infections and reptile bloodmeals. These rates were higher in G.p. gambiensis , and in the western part of the study area. T. vivax infections were related to cattle bloodmeals, and were more frequent in G. tachinoides and in the eastern study area. The PCR results combined with bloodmeal analysis helped us to establish the relationships between the vector and the host, to assess the trypanosome challenge in the two parts of the area, to elucidate the differences between the two types of T. congolense , and to suspect that most midgut infections were originating from reptilian trypanosomes.     

Fruit morphology in Tragopogon L. (Compositae: Lactuceae) from the Iberian Peninsula

Achenes of all the Tragopogon species from the Iberian Peninsula were examined by means of scanning-electron microscopy and stereomicroscopy. The achenes of the eight species are described, illustrated and compared. The results are contrasted with the systematics of this genus. The isolated position of T. lamottei with regard to the other seven species is noted. A key is provided to enable the different species to be distinguished.