鼻NK／T细胞淋巴瘤间质清道夫受体A的表达及意义

目的 观察清道夫受体A（scavenger receprorA,SR-A）在鼻NK／T细胞淋巴瘤间质中的表达,探讨其意义。方法 对鼻NK／T细胞淋巴瘤,鼻B细胞淋巴瘤以及鼻部炎症的石蜡标本进行HE染色和SP免疫组织化学染色检测SR-A的表达。结果 SR-A蛋白在鼻NK／T细胞淋巴瘤,鼻B细胞淋巴瘤和鼻部炎症中阳性率分别为92．7％,29．2％和6．25%。统计学分析发现,鼻NK／T细胞淋巴瘤中SR-A的表达与B细胞淋巴瘤和炎症中SR-A的表达均有显著差异（P〈0．001）。结论 SR-A可能在鼻NK／T细胞淋巴瘤的诊断及鉴别诊断中有一定的参考价值。     

Isolation and characterization of inhibitory factors of DNA polymerase III holoenzyme from Escherichia coli

Abstract Escherichia coli penicillin-binding protein 5 (PBP5) is anchored to the periplasmic face of the inner membrane via a C-terminal amphiphilic α-helix. The results of washing experiments have suggested an electrostatic contribution to the anchoring mechanism which may involve the cationic region of the C-terminal α-helix. Similarities between this anchor domain and some surface active agents, such as melittin, suggest that the cationic region of the PBP5 anchor may require the presence of anionic phospholipids for membrane interaction. Washing experiments performed on membranes of HDL11, an E. coli mutant in which the expression of the major anionic phospholipids is under lac control, found no such requirement. The results are discussed in relation to the hypothesis that the cationic region may interact with other sources of negative charge, possibly arising from a PBP complex.     

In vivo photochemical micronucleus induction due to certain quinolone antimicrobial agents in the skin of hairless mice

The skin micronucleus test combined with irradiation due to a sunlight simulator having a spectrum almost identical to solar irradiation was used as a novel in vivo testing method for detecting or comparing the photochemical chromosome damage of quinolone antibacterial agents (quinolones). Eight-week-old male SKH1 hairless mice were orally administered once lomefloxacin (LFLX), a strong in vitro photochemical clastogen, at 25 or 50 mg/kg, followed by light irradiation at 7.9–9.4 J/cm² of ultraviolet A (UVA). Animals were killed on Days 2, 3, 4, 5 or 8 (the dosing day was designated as Day 1), and the incidence of micronucleus in the epidermis was determined. As results, LFLX at either dose caused significant increases in the micronucleus frequency, which peaked on Day 4. These changes tended to return to the control level on Day 8. Then, the micronucleus induction potential of the quinolone derivatives levofloxacin (LVFX) and clinafloxacin (CLFX) at 10, 20 or 40 mg/kg was assessed on Day 4 under the same experimental conditions as for LFLX. Although LVFX was negative even at 40 mg/kg, CFLX dose-dependently induced significant increases in micronucleus frequency at all doses. The correlation of magnitude among the three quinolones in the skin micronucleus test with light irradiation was similar to that in our previous in vitro photochemical clastogenicity study. No significant increase in micronucleus frequency was observed in any of three quinolones employed without light irradiation. In conclusion, the experimental method presented here would be a useful tool for detecting in vivo photochemical chromosome damage and for research on photochemical carcinogenesis of chemicals.     

Preparation of monoclonal antibodies against planarian organs and the effect of fixatives

Monoclonal antibodies were obtained against all part of the body of the planarian Dugesia japonica japonica except tthe nerve cord, though parts of the enteric canal were also non reactive. The effect of a variety of fixatives (acetone, Bouin, formalin) used on planarian tissues prior to screening with antibodies, was assessed.     

Cytokine-inducing glycolipids in the lipoteichoic acid fraction from Enterococcus hirae ATCC 9790

Abstract Five high molecular weight glycolipids capable of stimulating human peripheral whole-blood cell cultures to cause interleukin 6 (IL-6) and tumor necrosis factor (TNF)-α induction were isolated from one of the lipoteichoic acid fractions (LTA-2) extracted from Enterococcus hirae ATCC 9790 (Tsutsui et al., (1991) FEMS Microbiol. Immunol. 76, 211–218) by a combination of hydrophobic interaction and anion-exchange chromatographies. This purification procedure resulted in a remarkable increase in the cytokine-inducing activities on the weight basis of isolated glycolipids (a maximum of 36- and 17-fold increases of IL-6 and TNF-α induction, respectively). The total yield of these bioactive glycolipids amounted to 6 wt% of the parent LTA-2 fraction, while the recovery rate in terms of the cytokine-inducing activities was estimated to be sufficient. The chemical composition and the profile, using SDS-PAGE, revealed that all of the isolated bioactive components were high molecular weight glycolipids, which were distinct from each other and from the parent LTA-2 fraction. These findings suggest that the IL-6 and TNF-α-inducing activities previously noted in the parent LTA-2 fraction are not attributable to a chemical entity, the structure of which had been proposed elsewhere (Fischer, W. (1990) in Glycolipids, Phosphoglycolipids and Sulfoglycolipids (Kates, M. ed.) pp. 123–234, Plenum Press, New York), but to the other high molecular weight glycolipids described here.     

Biomimetic one-pot synthesis of vinblastine: NAD(P)H-mediated vinblastine synthesis from the product of FMN-mediated vindoline–catharanthine coupling under near-ultraviolet light

Vinblastine (VLB) is an antineoplastic agent contained in leaves of Catharanthus roseus. One-pot synthesis of VLB from vindoline and catharanthine, biosynthetic precursors in the plant, was achieved under biomimetic conditions. FMN-mediated coupling of vindoline and catharanthine under irradiation with near-ultraviolet light was followed by NAD(P)H-mediated direct conversion of the coupling product to VLB in the dark. The yield of VLB was governed by the level of NAD(P)H added, and the highest yield was obtained by incubation with 10 mM NAD(P)H for 5 h. It is postulated, as one concept of VLB biosynthesis, that similar non-enzymic VLB synthesis may occur in the plant leaves.     

Large scale preparation of PA-oligosaccharides from glycoproteins using an improved extraction method

We have developed a new method for the large scale preparation of pyridylaminated (PA-) oligosaccharides from glycoproteins. Phenol/chloroform extration was adapted for the removal of protein and excess 2-aminopyridine, improving the efficiency of preparation. From a 2.5 g sample of human apo-transferrin, 25–30 mol of agalacto biantennary PA-oligosaccharide could be obtained. By increasing the concentration of PA-oligosaccharide substrate, we were able to detect a very low level ofN-acetylglucosaminlytransferase IV activity in CHO cell extracts.Abbreviations PA 2-aminopyridine - SDS sodium dodecyl sulfate - GlcNAc N-acetylglucosamine - GnT N-acetylglucosaminyltransferase - Gn,Gn-bi-PA GlcNAc1-2Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine - Gn,Gn,Gn-tri-PA GlcNAc1-2(GlcNAc1-4)Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine - Gn,Gn,Gn-trí-PA GlcNAc1-2Man1-3({GlcNAc1-2(GlcNAc1-6)Man1-6})Man1-4GlcNac1-4GlcNAc-2-aminopyridine - Gn,(Gn),Gn-bi-PA GlcNAc1-2Man1-3(GlcNAc1-4)(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine     

Characteristics and Pathogenicity of Non-Melibiose-Fermenting Strains of Yersinia pseudotuberculosis O3

The biological properties of non-melibiose-fermenting (NMF) strains of Yersinia pseudotuberculosis 03 were investigated. These strains were clearly distinguished from representative melibiose-fermenting (MF) strains of Y. pseudotuberculosis 03 by their pathogenicity in mice, sensitivity to some phages, production of catalase, restriction endonuclease analysis of virulence plasmid DNA with BamHI, detection of specific yersinia outer-membrane proteins with SDS-PAGE, antigenicity of the outer-membrane proteins and neutrophil resistance to phagocytosis. The pathogenicity of NMF strains was clearly less than that of MF strains. In addition, the resistance of NMF strains to phagocytosis and catalase activity was evidently weaker than that of MF strains. These results suggested that the difference of pathogenicity was due to the ability of catalase production. Although the relationship between the above characteristics and melibiose-fermentation was not analysed, the pathogenicity of Y. pseudotuberculosis 03 strains can probably be predicted by testing melibiose-fermentation and catalase production.