Investigation of recombinant Schistosoma japonicum paramyosin fragments for immunogenicity and vaccine efficacy in mice

Schistosoma japonicum paramyosin, a 97 kDa myofibrillar protein, is a recognized vaccine candidate against schistosomiasis. To improve its expression and to identify protective epitopic regions on paramyosin, the published Chinese Schistosoma japonicum paramyosin cDNA sequence was redesigned using Pichia codon usage and divided into four overlapping fragments （fragments 1, 2, 3, 4） of 747, 651, 669 and 678 bp, respectively. These gene fragments were synthesized and expressed in Pichia pastoris （fragments 2 and 3） or E. coli （fragments 1 and 4）. The recombinant proteins were produced at high level and purified using a two-step process involving Ni-NTA affinity chromatography and gel filtration. BALB/c mice were immunized subcutaneously three times at 2-week-intervals with the purified proteins formulated in adjuvant Quil A. The protein fragments were highly immunogenic, inducing high, though variable, ELISA antibody titres, and each was shown to resemble native paramyosin in terms of its recognition by the anti-fragment antibodies in Western blotting. The immunized mice were subjected to cercarial challenge 2 weeks after the final injection and promising protective efficacy in terms of significant reductions in worm burdens, worm-pair numbers and liver eggs in the vaccinated mice resulted. There was no apparent correlation between the antibody titres generated and protective efficacy, as all fragments produced effective but similar levels of protection.     

Relative and absolute bioavailability of prednisone and prednisolone after separate oral and intravenous doses

A randomized, four-way cross-over study was conducted in eight healthy male volunteers to determine the relative and absolute bioavailability of prednisone (PN) and prednisolone (PL). PN and PL were administered as single, oral 10-mg tablet doses and as 10-mg zero-order 0.5-hour intravenous infusions. Comparable mean PN and PL maximum plasma concentrations (Cmax), times for Cmax, areas under the plasma concentration-time curves (AUC), and apparent elimination rate constants between tablet treatments demonstrated that PN and PL tablets were bioequivalent. Absolute bioavailability (F) determinations based on plasma PL concentrations were independent of which IV treatment was used as reference and indicated complete systemic availability of PL from both PN and PL tablets. However, F based on plasma PN data was contradictory. Using IV PN as reference, approximately 70% systemic availability was observed from both tablets, whereas using IV PL as reference, systemic availability was greater than unity. PN and PL are model compounds that exemplify the difficulties involved in accurately determining the relative and absolute bioavailability of substances that undergo reversible metabolism.     

三七皂甙C1对四氧嘧啶糖尿病小鼠的降血糖作用

三匕皂甙Cl(简称Cl)能降低四氧嘧啶糖尿病小鼠血糖,效应随连续给药而增强,并呈量—效关系趋势,与胰岛素的降糖效应无协同或拮抗作用。单剂量Cl对四氧嘧啶糖尿病小鼠的血浆胰岛素和肝脏cAMP浓度无明显影响;但能促进大鼠分离肝细胞摄取[³H]葡萄糖,还能增加小鼠肝匀浆代谢葡萄糖和琥珀酸钠的耗氧量以及小鼠肝糖原的合成。     

Teleradiology: an assessment

A teleradiology system acquires radiographic images at one location and transmits them to one or more remote sites, where they are displayed and/or converted to hard copy. These systems often employ wide area networks. Their goal is to provide improved radiologic services at all sites on the network. Experience in the use of teleradiology systems has demonstrated the need for a laser film digitizer, an optical disk, and a high-quality display and/or laser film printer at each site. Single-site hardware purchase costs average $196,000, plus an additional 20% for yearly network services. Hardware purchased for a consultation or central referral facility approximates $344,000.     

压电石英传感器同时测定水溶液中维生素B1及维生素C

导出并经实验验证了压电传感器对维生素B₁及维生素C的频移线性校正模型,并用其实现了上述两种维生素制剂的同时测定。考虑到该药物体系可能存在一定程度的复共线关系,采用偏最小二乘线性校正技术处理实验数据。两种维生素浓度估计平均相对标准偏差分别为1.97%和2.47%,表明方法可行。     

碳环核苷类化合物的合成

通过氯代环戊烯和相应的嘧啶碱基缩合,再环氧化和开环得到了5′-去羟甲基碳环核苷类似物。所合成化合物经体外L₁₂₁₀和肝癌细胞筛选,并用2215细胞株进行抗乙肝病毒筛选,均未发现有意义的活性。     

Toxoplasmic scleritis

Although toxoplasmosis is the most common infectious cause of posterior intraocular inflammation, it is rarely described in association with scleritis. The authors present five cases of toxoplasmosis with scleritis. Two of the five cases were diagnosed clinically and serologically as having toxoplasmosis. Their retinochoroiditis and scleritis responded well to medical therapy. Retinochroiditis and scleritis that was refractory to treatment developed in the other three patients, two of whom had been receiving immunosuppressive therapy for systemic diseases. Their therapeutic regimens did not include treatment for toxoplasmosis. All three eyes became blind and were enucleated. Results of pathologic examination of all three enucleated eyes showed Toxoplasma gondii in the retina. There was severe inflammation of the retina, choroid, and sclera. Toxoplasmosis should be considered in the clinical differential diagnosis of scleritis associated with retinochoroiditis, particularly in immunosuppressed patients.