半抗原乙酰胆碱诱发抗体产生的时间规律

本文报道了半抗原乙酰胆碱免疫家兔产生抗体的最佳时间.与载体蛋白质不同,是在末次加强免疫后30～40天,而不是文献报道的7～14天.     

Synergistic inhibition of human leukemia cell growth by deoxyguanosine and 1-beta-D-arabinofuranosylcytosine

We studied the ability of 2'-deoxyguanosine (dGuo) to influence 1-beta-D-arabinofuranosylcytosine (ara-C) inhibition of soft agar cloning of the cultured human leukemia cell line K562. Ara-C alone inhibited cloning in concentrations of greater than 10 nM, with a steep drop in colony formation observed between 10 and 100 nM. dGuo and ara-C synergistically inhibited cloning; the combination of ineffective concentrations of dGuo (10-50 microM) and ara-C (less than or equal to nM) inhibited cloning by 40-70%. In K562 cells, dGuo is metabolized by both nucleoside kinase and purine nucleoside phosphorylase (PNP), resulting in augmentation of both the GTP pool (to more than 200% of control after a 3 hr incubation with 500 microM dGuo) and the dGTP pool (to more than 2700% of control after 3 hr with 500 microM dGuo). dGuo (50-500 microM) caused a decrease in the dCTP and dTTP pools and an increase in the dATP pool. Synergistic concentrations of dGuo plus 10 nM ara-C augmented the ara-CTP pool up to 800% of control after 3 hr to levels equivalent to those observed after incubation with 500 nM ara-C alone. Incorporation of 10 nM ara-CTP into DNA also increased in the presence of dGuo (up to a maximum of 300% of control), but only to a level that approximated the value observed with nM ara-C alone. The disparity between enlargement of the ara-CTP pool and augmentation of ara-C incorporation into DNA is consistent with the observation of Steinberg et al. [Cancer Res. 39, 4330 (1979)] that high concentrations of dGTP may inhibit DNA polymerase activity. Thus, synergy between dGuo and ara-C is multifactorial, possibly involving inhibition of DNA polymerase by elevated dGTP and ara-CTP pools and augmented incorporation of ara-C into DNA.     

The in vitro effect of electromagnetically generated shock waves (Lithostar) on the Dunning R3327 PAT-2 rat prostatic cancer cell-line

Summary High energy shock wave lithotripsy has proven to be an effective tool in the management of renal calculi. The effects of electrohydraulically generated high energy shock waves (HESW) on tumor cells were described only recently. Here we present data on the experimental design for treatment of tumor cells, using electromagnetically generated shock waves. The dertermination of the focal area, in which pressures are at least 50% of the maximum pressure, appeared to be essential. In vitro HESW treatment resulted in a dose dependant anti-proliferative effect on Dunning R-3327 PAT-2 rat prostate cancer subline, determined by temporal growth curve analysis after plating of treated cells in soft agar. Furthermore, it was shown that HESW treatment had a potentiating effect on Vinblastin treatment. The combination of HESW with Vinblastin appeared to have an additive in vitro antiproliferative effect on PAT-2 prostatic cancer cells.     

Staib Agar Supplemented with a Triple Antibiotic Combination for the Detection of Cryptococcus neoformtans in Clinical Specimens: Staib-Agar mit einer Dreifach-Antibiotika-Kombination für den Nachweis von Cryptococcus neoformans in klinischem Untersuchungsmaterial

It was demonstrated that the in vitro growth of a mucoid Escherichia coli strain from the urine of an AIDS patient could disturb the concurrent growth of Cryptococcus neoformans and the development of its brown colour effect (BCE) on Staib agar (syn. Guizotia abyssinica creatinine agar, bird seed agar, niger seed agar etc.) supplemented with penicillin + streptomycin. Owing to the supplementation with the triple antibiotic combination of penicillin + streptomycin + gentamicin and the resulting inhibition of E. coli growth, the formation of an intense BCE of the Cr. neoformans colonies after 3 d at 26 degrees C could be observed. On the same medium supplemented with this triple antibiotic combination 40 Cr. neoformans strains tested showed growth with an intense BCE after 3 d at 26 degrees C; but on Emmons' neutral Sabouraud's dextrose agar (NSDA) supplemented with the same triple antibiotic combination, inhibition of growth was found. For the examination of clinical specimens for Cr. neoformans contaminated with gram-negative rod-like bacteria, Staib agar supplemented with this triple antibiotic combination is proposed. Various antibiotic supplements to primary recovery media for fungi are discussed and ecological interrelations of bacteria and fungi are emphasized.     

Reed-Sternberg cells cultured from morphologically unidentifiable precursors in the blood of patients with Hodgkin's disease

In order to examine whether morphologically unidentifiable precursors of Reed-Sternberg cells (RSC) may circulate in the blood of patients with untreated Hodgkin's Disease (HD), mononuclear leukocytes were isolated from the blood of 33 consecutive patients and cultured in soft agar. Abnormal colonies containing multinucleated giant cells developed in the specimens of 12 patients. These cells had the light and electron microscopic appearance of RSC. They were positive for alpha-naphthyl acetate and alpha-naphthyl butyrate esterases, acid phosphatase and lysozyme, bespeaking their monocyte/macrophage lineage. The observations suggest that unidentifiable precursors of RSC could be responsible for hematogenous spread of the disease in some cases. Moreover, since RS-like cells developed in the specimens of 8 patients with stage I and II HD, it may be useful to evaluate whether soft agar colony culture would yield data of prognostic significance in patients with early disease.     

Evaluation of normal ocular bacterial flora with two different culture media

BACKGROUND: The purpose of this study was to determine if the use of broth culture medium is efficient in investigating bacterial flora of the normal eyelid and conjunctiva. METHODS: Samples from the conjunctiva and eyelid of healthy patients of various ages who were undergoing ocular surgeries were obtained and cultured at 3 periods: before topical antibiotic prophylaxis, in the postoperative period during topical antibiotic treatment, and 15 days after discontinuation of antibiotic use. Samples were inoculated into both brain heart infusion broth and blood agar plate, and the growth results of both media were analyzed. RESULTS: Brain heart infusion broth medium showed a significantly higher bacterial growth of gram-positive cocci in most periods. The solid blood agar medium had a higher recovery of gram-positive bacilli before prophylaxis only in the older patients. INTERPRETATION: Our results show that a more complete analysis of eyelid and conjunctival flora can be obtained using both liquid and solid media to increase the chances of isolate recovery. The inclusion of liquid media in this analysis was even more relevant in the period of concomitant use of antibiotic treatment.     

七氟醚预处理对心肌缺血再灌注大鼠心肌线粒体蛋白质组学双向凝胶电泳分析

[目的]研究七氟醚预处理对缺血再灌注心肌保护的线粒体相关蛋白的变化.[方法]采用双向凝胶电泳技术对七氟醚预处理（S组）与对照组（C组）大鼠心肌线粒体蛋白质进行分离和比较分析.[结果]S组与C组相比,有21个蛋白质表达发生了改变,其中表达增强的有17个蛋白,表达降低的有4个蛋白.[结论]这些差异表达的蛋白质可能参与了七氟醚预处理对心肌的保护作用.     

Accuracy of three different electronic apex locators in detecting simulated horizontal and vertical root fractures

The aim of this in vitro study was to evaluate the accuracy of three electronic apex locators (EALs): Root ZX, Foramatron D10 and Apex NRG, in the detection of fractures in teeth having simulated horizontal and vertical root fractures. A total of 90 extracted intact, straight, single-rooted teeth were divided into six groups of 15 teeth each. In Groups A, B and C, an incomplete horizontal fracture was simulated by preparing a horizontal incision in the coronal, middle or apical portion of the root until the circumferential half of the canal was exposed in the horizontal plane respectively. In Groups D, E and F, an incomplete vertical root fracture was simulated by preparing a vertical straight incision to expose the canal in the coronal, middle or apical portion of the root all the way in the longitudinal plane respectively. The simulated fractures were 0.25 mm in thickness in all groups. The teeth were embedded in 1% agar and the canals were irrigated with saline solution during electronic measurement. Detection of the simulated root fractures was established with a size 10 K-file when the meter value reached 'APEX' on each EAL. In Groups A, B and C, Kruskal-Wallis tests revealed that there were no statistically significant differences between the three EALs. However, statistically significant differences were found among the EALs in Groups D, E and F (P < 0.0001, one-way anova and Tukey's post-hoc test). In conclusion, the three EALs tested were accurate and acceptable clinical tools in the detection of horizontal root fractures. However, the three EALs were unreliable in detecting the position of vertical root fractures.     

Candida albicans is an immunogen for anti-Saccharomyces cerevisiae antibody markers of Crohn's disease

BACKGROUND AND AIMS: Antibodies directed against oligomannose sequences alpha-1,3 Man (alpha-1,2 Man alpha-1,2 Man)(n) (n = 1 or 2), termed anti-Saccharomyces cerevisiae antibodies (ASCAs) are markers of Crohn's disease (CD). S. cerevisiae mannan, which expresses these haptens, is used to detect ASCA, but the exact immunogen for ASCA is unknown. Structural and genetic studies have shown that Candida albicans produces mannosyltransferase enzymes that can synthesize S cerevisiae oligomannose sequences depending on growth conditions. This study investigated whether C. albicans could act as an immunogen for ASCA. METHODS: Sequential sera were collected from patients with CD, systemic candidiasis, and rabbits infected with C. albicans. Antibodies were purified by using chemically synthesized (Sigma) ASCA major epitopes. These affinity-purified antibodies and lectins were then used to analyze the expression of ASCA epitopes on molecular extracts and cell walls of C. albicans and S cerevisiae grown in various conditions. RESULTS: In humans and rabbits, generation of ASCA was shown to be associated with the generation of anti-C. albicans antibodies resulting specifically from infection. By using affinity-purified antibodies, C. albicans was shown to express ASCA epitopes on mannoproteins similar to those of S. cerevisiae. By changing the growth conditions, C. albicans mannan was also able to mimic S. cerevisiae mannan in its ability to detect ASCA associated with CD. This overexpression of ASCA epitopes was achieved when C. albicans grew in human tissues. CONCLUSIONS: C. albicans is one of several immunogens for ASCA and may be at the origin of an aberrant immune response in CD.